2001-10-03 23:19:58 +02:00
drop table if exists t1,t2,t3,t4,t5,t6;
2003-06-27 15:29:10 +02:00
drop database if exists mysqltest;
2001-09-28 07:05:54 +02:00
create table t1 (a int not null primary key auto_increment, message char(20));
create table t2 (a int not null primary key auto_increment, message char(20));
INSERT INTO t1 (message) VALUES ("Testing"),("table"),("t1");
INSERT INTO t2 (message) VALUES ("Testing"),("table"),("t2");
2003-12-10 05:31:42 +01:00
create table t3 (a int not null, b char(20), key(a)) engine=MERGE UNION=(t1,t2);
2001-09-28 07:05:54 +02:00
select * from t3;
2000-12-28 02:56:38 +01:00
a b
1 Testing
2 table
3 t1
1 Testing
2 table
3 t2
2001-09-28 07:05:54 +02:00
select * from t3 order by a desc;
2000-12-28 02:56:38 +01:00
a b
3 t1
3 t2
2 table
2 table
1 Testing
1 Testing
2001-09-28 07:05:54 +02:00
drop table t3;
insert into t1 select NULL,message from t2;
insert into t2 select NULL,message from t1;
insert into t1 select NULL,message from t2;
insert into t2 select NULL,message from t1;
insert into t1 select NULL,message from t2;
insert into t2 select NULL,message from t1;
insert into t1 select NULL,message from t2;
insert into t2 select NULL,message from t1;
insert into t1 select NULL,message from t2;
insert into t2 select NULL,message from t1;
insert into t1 select NULL,message from t2;
2003-12-10 05:31:42 +01:00
create table t3 (a int not null, b char(20), key(a)) engine=MERGE UNION=(test.t1,test.t2);
2001-09-28 07:05:54 +02:00
explain select * from t3 where a < 10;
2002-09-26 22:08:22 +02:00
id select_type table type possible_keys key key_len ref rows Extra
2002-11-21 21:25:53 +01:00
1 SIMPLE t3 range a a 4 NULL 18 Using where
2001-09-28 07:05:54 +02:00
explain select * from t3 where a > 10 and a < 20;
2002-09-26 22:08:22 +02:00
id select_type table type possible_keys key key_len ref rows Extra
2005-05-13 11:08:08 +02:00
1 SIMPLE t3 range a a 4 NULL 17 Using where
2001-09-28 07:05:54 +02:00
select * from t3 where a = 10;
2000-12-28 02:56:38 +01:00
a b
10 Testing
10 Testing
2001-09-28 07:05:54 +02:00
select * from t3 where a < 10;
2000-12-28 02:56:38 +01:00
a b
1 Testing
1 Testing
2 table
2 table
3 t1
3 t2
4 Testing
4 Testing
5 table
5 table
6 t2
2006-02-11 19:51:43 +01:00
6 t1
2000-12-28 02:56:38 +01:00
7 Testing
7 Testing
8 table
8 table
9 t2
9 t2
2001-09-28 07:05:54 +02:00
select * from t3 where a > 10 and a < 20;
2000-12-28 02:56:38 +01:00
a b
11 table
11 table
12 t1
12 t1
13 Testing
13 Testing
14 table
14 table
15 t2
15 t2
16 Testing
16 Testing
17 table
17 table
18 t2
18 t2
19 Testing
19 Testing
2001-09-28 07:05:54 +02:00
explain select a from t3 order by a desc limit 10;
2002-09-26 22:08:22 +02:00
id select_type table type possible_keys key key_len ref rows Extra
2007-08-02 21:45:56 +02:00
1 SIMPLE t3 index NULL a 4 NULL 10 Using index
2001-09-28 07:05:54 +02:00
select a from t3 order by a desc limit 10;
2000-12-28 02:56:38 +01:00
a
699
698
697
696
695
694
693
692
691
690
2001-09-28 07:05:54 +02:00
select a from t3 order by a desc limit 300,10;
2000-12-28 02:56:38 +01:00
a
416
415
415
414
414
413
413
412
412
411
2001-10-03 23:19:58 +02:00
delete from t3 where a=3;
select * from t3 where a < 10;
a b
1 Testing
1 Testing
2 table
2 table
4 Testing
4 Testing
5 table
5 table
6 t2
6 t1
7 Testing
7 Testing
8 table
8 table
9 t2
9 t2
delete from t3 where a >= 6 and a <= 8;
select * from t3 where a < 10;
a b
1 Testing
1 Testing
2 table
2 table
4 Testing
4 Testing
5 table
5 table
9 t2
9 t2
update t3 set a=3 where a=9;
select * from t3 where a < 10;
a b
1 Testing
1 Testing
2 table
2 table
3 t2
3 t2
4 Testing
4 Testing
5 table
5 table
update t3 set a=6 where a=7;
select * from t3 where a < 10;
a b
1 Testing
1 Testing
2 table
2 table
3 t2
3 t2
4 Testing
4 Testing
5 table
5 table
2001-09-28 07:05:54 +02:00
show create table t3;
2001-02-17 18:04:33 +01:00
Table Create Table
t3 CREATE TABLE `t3` (
2004-10-02 21:20:08 +02:00
`a` int(11) NOT NULL,
2006-02-22 10:09:59 +01:00
`b` char(20) DEFAULT NULL,
2001-02-17 18:04:33 +01:00
KEY `a` (`a`)
2003-12-10 05:31:42 +01:00
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`t1`,`t2`)
create table t4 (a int not null, b char(10), key(a)) engine=MERGE UNION=(t1,t2);
2001-09-28 07:05:54 +02:00
select * from t4;
2006-10-06 07:54:47 +02:00
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
2003-06-27 15:29:10 +02:00
alter table t4 add column c int;
2006-10-06 07:54:47 +02:00
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
2005-11-23 21:45:02 +01:00
flush tables;
select * from t4;
2006-10-06 08:09:58 +02:00
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
2003-06-27 15:29:10 +02:00
create database mysqltest;
create table mysqltest.t6 (a int not null primary key auto_increment, message char(20));
2003-12-10 05:31:42 +01:00
create table t5 (a int not null, b char(20), key(a)) engine=MERGE UNION=(test.t1,mysqltest.t6);
2003-06-27 15:29:10 +02:00
show create table t5;
Table Create Table
t5 CREATE TABLE `t5` (
2004-10-02 21:20:08 +02:00
`a` int(11) NOT NULL,
2006-02-22 10:09:59 +01:00
`b` char(20) DEFAULT NULL,
2003-06-27 15:29:10 +02:00
KEY `a` (`a`)
2003-12-10 05:31:42 +01:00
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`t1`,`mysqltest`.`t6`)
alter table t5 engine=myisam;
2003-06-27 15:29:10 +02:00
drop table t5, mysqltest.t6;
drop database mysqltest;
2003-07-01 14:49:32 +02:00
drop table t4,t3,t1,t2;
2003-12-10 05:31:42 +01:00
create table t1 (c char(10)) engine=myisam;
create table t2 (c char(10)) engine=myisam;
create table t3 (c char(10)) union=(t1,t2) engine=merge;
2001-09-28 07:05:54 +02:00
insert into t1 (c) values ('test1');
insert into t1 (c) values ('test1');
insert into t1 (c) values ('test1');
insert into t2 (c) values ('test2');
insert into t2 (c) values ('test2');
insert into t2 (c) values ('test2');
select * from t3;
2000-12-28 02:56:38 +01:00
c
test1
test1
test1
test2
test2
test2
2001-09-28 07:05:54 +02:00
select * from t3;
2000-12-28 02:56:38 +01:00
c
test1
test1
test1
test2
test2
test2
2001-09-28 07:05:54 +02:00
delete from t3 where 1=1;
select * from t3;
2000-12-28 02:56:38 +01:00
c
2001-09-28 07:05:54 +02:00
select * from t1;
2000-12-28 02:56:38 +01:00
c
2001-09-28 07:05:54 +02:00
drop table t3,t2,t1;
CREATE TABLE t1 (incr int not null, othr int not null, primary key(incr));
CREATE TABLE t2 (incr int not null, othr int not null, primary key(incr));
CREATE TABLE t3 (incr int not null, othr int not null, primary key(incr))
2003-12-10 05:31:42 +01:00
ENGINE=MERGE UNION=(t1,t2);
2001-09-28 07:05:54 +02:00
SELECT * from t3;
2000-12-28 02:56:38 +01:00
incr othr
2001-09-28 07:05:54 +02:00
INSERT INTO t1 VALUES ( 1,10),( 3,53),( 5,21),( 7,12),( 9,17);
INSERT INTO t2 VALUES ( 2,24),( 4,33),( 6,41),( 8,26),( 0,32);
INSERT INTO t1 VALUES (11,20),(13,43),(15,11),(17,22),(19,37);
INSERT INTO t2 VALUES (12,25),(14,31),(16,42),(18,27),(10,30);
SELECT * from t3 where incr in (1,2,3,4) order by othr;
2000-12-28 02:56:38 +01:00
incr othr
1 10
2 24
4 33
3 53
2001-09-28 07:05:54 +02:00
alter table t3 UNION=(t1);
select count(*) from t3;
2001-01-28 20:35:50 +01:00
count(*)
10
2001-09-28 07:05:54 +02:00
alter table t3 UNION=(t1,t2);
select count(*) from t3;
2001-01-28 20:35:50 +01:00
count(*)
20
2003-12-10 05:31:42 +01:00
alter table t3 ENGINE=MYISAM;
2001-09-28 07:05:54 +02:00
select count(*) from t3;
2001-01-28 20:35:50 +01:00
count(*)
20
2001-09-28 07:05:54 +02:00
drop table t3;
CREATE TABLE t3 (incr int not null, othr int not null, primary key(incr))
2003-12-10 05:31:42 +01:00
ENGINE=MERGE UNION=(t1,t2);
2001-09-28 07:05:54 +02:00
show create table t3;
2001-03-06 14:24:08 +01:00
Table Create Table
t3 CREATE TABLE `t3` (
2004-10-02 21:20:08 +02:00
`incr` int(11) NOT NULL,
`othr` int(11) NOT NULL,
2006-02-02 20:39:28 +01:00
PRIMARY KEY (`incr`)
2003-12-10 05:31:42 +01:00
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`t1`,`t2`)
2001-09-28 07:05:54 +02:00
alter table t3 drop primary key;
show create table t3;
2001-03-06 14:24:08 +01:00
Table Create Table
t3 CREATE TABLE `t3` (
2004-10-02 21:20:08 +02:00
`incr` int(11) NOT NULL,
`othr` int(11) NOT NULL
2003-12-10 05:31:42 +01:00
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`t1`,`t2`)
2001-09-28 07:05:54 +02:00
drop table t3,t2,t1;
2003-12-10 05:31:42 +01:00
create table t1 (a int not null, key(a)) engine=merge;
2001-09-28 07:05:54 +02:00
select * from t1;
2010-05-31 15:38:02 +02:00
a
2001-09-28 07:05:54 +02:00
drop table t1;
create table t1 (a int not null, b int not null, key(a,b));
create table t2 (a int not null, b int not null, key(a,b));
2003-12-10 05:31:42 +01:00
create table t3 (a int not null, b int not null, key(a,b)) ENGINE=MERGE UNION=(t1,t2);
2001-09-28 07:05:54 +02:00
insert into t1 values (1,2),(2,1),(0,0),(4,4),(5,5),(6,6);
insert into t2 values (1,1),(2,2),(0,0),(4,4),(5,5),(6,6);
flush tables;
select * from t3 where a=1 order by b limit 2;
2001-05-16 23:06:30 +02:00
a b
1 1
1 2
2001-09-28 07:05:54 +02:00
drop table t3,t1,t2;
2002-07-21 23:55:32 +02:00
create table t1 (a int not null, b int not null auto_increment, primary key(a,b));
create table t2 (a int not null, b int not null auto_increment, primary key(a,b));
2001-10-03 23:19:58 +02:00
create table t3 (a int not null, b int not null, key(a,b)) UNION=(t1,t2) INSERT_METHOD=NO;
2003-12-10 05:31:42 +01:00
create table t4 (a int not null, b int not null, key(a,b)) ENGINE=MERGE UNION=(t1,t2) INSERT_METHOD=NO;
create table t5 (a int not null, b int not null auto_increment, primary key(a,b)) ENGINE=MERGE UNION=(t1,t2) INSERT_METHOD=FIRST;
create table t6 (a int not null, b int not null auto_increment, primary key(a,b)) ENGINE=MERGE UNION=(t1,t2) INSERT_METHOD=LAST;
2001-10-03 23:19:58 +02:00
show create table t3;
Table Create Table
t3 CREATE TABLE `t3` (
2004-10-02 21:20:08 +02:00
`a` int(11) NOT NULL,
`b` int(11) NOT NULL,
2001-10-03 23:19:58 +02:00
KEY `a` (`a`,`b`)
2003-12-10 05:31:42 +01:00
) ENGINE=MyISAM DEFAULT CHARSET=latin1
2001-10-03 23:19:58 +02:00
show create table t4;
Table Create Table
t4 CREATE TABLE `t4` (
2004-10-02 21:20:08 +02:00
`a` int(11) NOT NULL,
`b` int(11) NOT NULL,
2001-10-03 23:19:58 +02:00
KEY `a` (`a`,`b`)
2003-12-10 05:31:42 +01:00
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`t1`,`t2`)
2001-10-03 23:19:58 +02:00
show create table t5;
Table Create Table
t5 CREATE TABLE `t5` (
2004-10-02 21:20:08 +02:00
`a` int(11) NOT NULL,
2006-02-22 10:09:59 +01:00
`b` int(11) NOT NULL AUTO_INCREMENT,
2006-02-02 20:39:28 +01:00
PRIMARY KEY (`a`,`b`)
2003-12-10 05:31:42 +01:00
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 INSERT_METHOD=FIRST UNION=(`t1`,`t2`)
2001-10-03 23:19:58 +02:00
show create table t6;
Table Create Table
t6 CREATE TABLE `t6` (
2004-10-02 21:20:08 +02:00
`a` int(11) NOT NULL,
2006-02-22 10:09:59 +01:00
`b` int(11) NOT NULL AUTO_INCREMENT,
2006-02-02 20:39:28 +01:00
PRIMARY KEY (`a`,`b`)
2003-12-10 05:31:42 +01:00
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 INSERT_METHOD=LAST UNION=(`t1`,`t2`)
2002-07-21 23:55:32 +02:00
insert into t1 values (1,NULL),(1,NULL),(1,NULL),(1,NULL);
insert into t2 values (2,NULL),(2,NULL),(2,NULL),(2,NULL);
2001-10-03 23:19:58 +02:00
select * from t3 order by b,a limit 3;
a b
select * from t4 order by b,a limit 3;
a b
1 1
2 1
1 2
select * from t5 order by b,a limit 3,3;
a b
2 2
1 3
2 3
select * from t6 order by b,a limit 6,3;
a b
1 4
2 4
insert into t5 values (5,1),(5,2);
insert into t6 values (6,1),(6,2);
select * from t1 order by a,b;
a b
1 1
1 2
1 3
1 4
5 1
5 2
select * from t2 order by a,b;
a b
2 1
2 2
2 3
2 4
6 1
6 2
select * from t4 order by a,b;
a b
1 1
1 2
1 3
1 4
2 1
2 2
2 3
2 4
5 1
5 2
6 1
6 2
insert into t3 values (3,1),(3,2),(3,3),(3,4);
select * from t3 order by a,b;
a b
3 1
3 2
3 3
3 4
alter table t4 UNION=(t1,t2,t3);
show create table t4;
Table Create Table
t4 CREATE TABLE `t4` (
2004-10-02 21:20:08 +02:00
`a` int(11) NOT NULL,
`b` int(11) NOT NULL,
2001-10-03 23:19:58 +02:00
KEY `a` (`a`,`b`)
2003-12-10 05:31:42 +01:00
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`t1`,`t2`,`t3`)
2001-10-03 23:19:58 +02:00
select * from t4 order by a,b;
a b
1 1
1 2
1 3
1 4
2 1
2 2
2 3
2 4
3 1
3 2
3 3
3 4
5 1
5 2
6 1
6 2
alter table t4 INSERT_METHOD=FIRST;
show create table t4;
Table Create Table
t4 CREATE TABLE `t4` (
2004-10-02 21:20:08 +02:00
`a` int(11) NOT NULL,
`b` int(11) NOT NULL,
2001-10-03 23:19:58 +02:00
KEY `a` (`a`,`b`)
2003-12-10 05:31:42 +01:00
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 INSERT_METHOD=FIRST UNION=(`t1`,`t2`,`t3`)
2001-10-03 23:19:58 +02:00
insert into t4 values (4,1),(4,2);
select * from t1 order by a,b;
a b
1 1
1 2
1 3
1 4
4 1
4 2
5 1
5 2
select * from t2 order by a,b;
a b
2 1
2 2
2 3
2 4
6 1
6 2
select * from t3 order by a,b;
a b
3 1
3 2
3 3
3 4
select * from t4 order by a,b;
a b
1 1
1 2
1 3
1 4
2 1
2 2
2 3
2 4
3 1
3 2
3 3
3 4
4 1
4 2
5 1
5 2
6 1
6 2
select * from t5 order by a,b;
a b
1 1
1 2
1 3
1 4
2 1
2 2
2 3
2 4
4 1
4 2
5 1
5 2
6 1
6 2
2002-07-21 23:55:32 +02:00
select 1;
1
1
insert into t5 values (1,NULL),(5,NULL);
insert into t6 values (2,NULL),(6,NULL);
select * from t1 order by a,b;
a b
1 1
1 2
1 3
1 4
1 5
4 1
4 2
5 1
5 2
5 3
select * from t2 order by a,b;
a b
2 1
2 2
2 3
2 4
2 5
6 1
6 2
6 3
select * from t5 order by a,b;
a b
1 1
1 2
1 3
1 4
1 5
2 1
2 2
2 3
2 4
2 5
4 1
4 2
5 1
5 2
5 3
6 1
6 2
6 3
select * from t6 order by a,b;
a b
1 1
1 2
1 3
1 4
1 5
2 1
2 2
2 3
2 4
2 5
4 1
4 2
5 1
5 2
5 3
6 1
6 2
6 3
2003-07-01 14:49:32 +02:00
insert into t1 values (99,NULL);
select * from t4 where a+0 > 90;
a b
99 1
2004-06-25 15:12:13 +02:00
insert t5 values (1,1);
2006-01-23 12:17:05 +01:00
ERROR 23000: Duplicate entry '1-1' for key 'PRIMARY'
2004-06-25 15:12:13 +02:00
insert t6 values (2,1);
2006-01-23 12:17:05 +01:00
ERROR 23000: Duplicate entry '2-1' for key 'PRIMARY'
2004-06-25 15:12:13 +02:00
insert t5 values (1,1) on duplicate key update b=b+10;
insert t6 values (2,1) on duplicate key update b=b+20;
select * from t5 where a < 3;
a b
1 2
1 3
1 4
1 5
1 11
2 2
2 3
2 4
2 5
2 21
2003-07-01 14:49:32 +02:00
drop table t6, t5, t4, t3, t2, t1;
2003-12-10 05:31:42 +01:00
CREATE TABLE t1 ( a int(11) NOT NULL default '0', b int(11) NOT NULL default '0', PRIMARY KEY (a,b)) ENGINE=MyISAM;
2002-06-15 19:59:42 +02:00
INSERT INTO t1 VALUES (1,1), (2,1);
2003-12-10 05:31:42 +01:00
CREATE TABLE t2 ( a int(11) NOT NULL default '0', b int(11) NOT NULL default '0', PRIMARY KEY (a,b)) ENGINE=MyISAM;
2002-06-15 19:59:42 +02:00
INSERT INTO t2 VALUES (1,2), (2,2);
2003-12-10 05:31:42 +01:00
CREATE TABLE t3 ( a int(11) NOT NULL default '0', b int(11) NOT NULL default '0', KEY a (a,b)) ENGINE=MRG_MyISAM UNION=(t1,t2);
2003-01-06 00:48:59 +01:00
select max(b) from t3 where a = 2;
2002-06-15 19:59:42 +02:00
max(b)
2003-01-17 12:48:23 +01:00
2
2002-06-18 16:38:06 +02:00
select max(b) from t1 where a = 2;
max(b)
1
2003-07-01 14:49:32 +02:00
drop table t3,t1,t2;
2009-12-03 00:09:22 +01:00
CREATE TABLE t1 (c1 INT NOT NULL);
CREATE TABLE t2 (c1 INT NOT NULL);
INSERT INTO t1 VALUES (1);
INSERT INTO t2 VALUES (2);
CREATE TEMPORARY TABLE t3 (c1 INT NOT NULL) ENGINE=MRG_MYISAM UNION=(t1,t2);
SELECT * FROM t3;
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
2009-12-03 00:09:22 +01:00
CREATE TEMPORARY TABLE t4 (c1 INT NOT NULL);
CREATE TEMPORARY TABLE t5 (c1 INT NOT NULL);
INSERT INTO t4 VALUES (4);
INSERT INTO t5 VALUES (5);
CREATE TEMPORARY TABLE t6 (c1 INT NOT NULL) ENGINE=MRG_MYISAM UNION=(t4,t5);
SELECT * FROM t6;
c1
4
5
DROP TABLE t6, t3, t1, t2, t4, t5;
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
create temporary table t1 (a int not null);
create temporary table t2 (a int not null);
insert into t1 values (1);
insert into t2 values (2);
create table t3 (a int not null) ENGINE=MERGE UNION=(t1,t2);
select * from t3;
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
drop table t3, t2, t1;
create table t1 (a int not null);
create temporary table t2 (a int not null);
insert into t1 values (1);
insert into t2 values (2);
create table t3 (a int not null) ENGINE=MERGE UNION=(t1,t2);
select * from t3;
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
drop table t3;
create temporary table t3 (a int not null) ENGINE=MERGE UNION=(t1,t2);
select * from t3;
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
drop table t3, t2, t1;
# CREATE...SELECT is not implemented for MERGE tables.
CREATE TEMPORARY TABLE t1 (c1 INT NOT NULL);
CREATE TEMPORARY TABLE t2 (c1 INT NOT NULL);
CREATE TABLE t3 (c1 INT NOT NULL);
INSERT INTO t3 VALUES (3), (33);
LOCK TABLES t3 READ;
CREATE TEMPORARY TABLE t4 (c1 INT NOT NULL) ENGINE=MERGE UNION=(t1,t2)
INSERT_METHOD=LAST SELECT * FROM t3;
ERROR HY000: 'test.t4' is not BASE TABLE
SELECT * FROM t4;
ERROR HY000: Table 't4' was not locked with LOCK TABLES
UNLOCK TABLES;
CREATE TEMPORARY TABLE t4 (c1 INT NOT NULL) ENGINE=MERGE UNION=(t1,t2)
INSERT_METHOD=LAST;
INSERT INTO t4 SELECT * FROM t3;
# Alter temporary MERGE table.
ALTER TABLE t4 UNION=(t1);
LOCK TABLES t4 WRITE;
# Alter temporary MERGE table under LOCk tables.
ALTER TABLE t4 UNION=(t1,t2);
UNLOCK TABLES;
# MERGE table and function.
CREATE FUNCTION f1 () RETURNS INT RETURN (SELECT max(c1) FROM t3);
SELECT * FROM t4 WHERE c1 < f1();
c1
3
DROP FUNCTION f1;
DROP TABLE t4, t3, t2, t1;
2002-11-17 18:58:03 +01:00
CREATE TABLE t1 (
fileset_id tinyint(3) unsigned NOT NULL default '0',
file_code varchar(32) NOT NULL default '',
fileset_root_id tinyint(3) unsigned NOT NULL default '0',
PRIMARY KEY (fileset_id,file_code),
KEY files (fileset_id,fileset_root_id)
2003-12-10 05:31:42 +01:00
) ENGINE=MyISAM;
2002-11-17 18:58:03 +01:00
INSERT INTO t1 VALUES (2, '0000000111', 1), (2, '0000000112', 1), (2, '0000000113', 1),
(2, '0000000114', 1), (2, '0000000115', 1), (2, '0000000116', 1), (2, '0000000117', 1),
(2, '0000000118', 1), (2, '0000000119', 1), (2, '0000000120', 1);
CREATE TABLE t2 (
fileset_id tinyint(3) unsigned NOT NULL default '0',
file_code varchar(32) NOT NULL default '',
fileset_root_id tinyint(3) unsigned NOT NULL default '0',
PRIMARY KEY (fileset_id,file_code),
KEY files (fileset_id,fileset_root_id)
2003-12-10 05:31:42 +01:00
) ENGINE=MRG_MyISAM UNION=(t1);
2002-11-17 18:58:03 +01:00
EXPLAIN SELECT * FROM t2 IGNORE INDEX (files) WHERE fileset_id = 2
AND file_code BETWEEN '0000000115' AND '0000000120' LIMIT 1;
2002-11-21 21:25:53 +01:00
id select_type table type possible_keys key key_len ref rows Extra
2004-12-06 01:00:37 +01:00
1 SIMPLE t2 range PRIMARY PRIMARY 35 NULL 5 Using where
2002-11-17 18:58:03 +01:00
EXPLAIN SELECT * FROM t2 WHERE fileset_id = 2
AND file_code BETWEEN '0000000115' AND '0000000120' LIMIT 1;
2002-11-21 21:25:53 +01:00
id select_type table type possible_keys key key_len ref rows Extra
2004-12-06 01:00:37 +01:00
1 SIMPLE t2 range PRIMARY,files PRIMARY 35 NULL 5 Using where
2002-11-17 18:58:03 +01:00
EXPLAIN SELECT * FROM t1 WHERE fileset_id = 2
AND file_code BETWEEN '0000000115' AND '0000000120' LIMIT 1;
2002-11-21 21:25:53 +01:00
id select_type table type possible_keys key key_len ref rows Extra
2004-12-06 01:00:37 +01:00
1 SIMPLE t1 range PRIMARY,files PRIMARY 35 NULL 5 Using where
2002-11-17 18:58:03 +01:00
EXPLAIN SELECT * FROM t2 WHERE fileset_id = 2
AND file_code = '0000000115' LIMIT 1;
2002-11-21 21:25:53 +01:00
id select_type table type possible_keys key key_len ref rows Extra
2006-10-16 17:09:58 +02:00
1 SIMPLE t2 const PRIMARY,files PRIMARY 35 const,const 1
2003-01-06 00:48:59 +01:00
DROP TABLE t2, t1;
2003-07-03 10:55:36 +02:00
create table t1 (x int, y int, index xy(x, y));
create table t2 (x int, y int, index xy(x, y));
2003-12-10 05:31:42 +01:00
create table t3 (x int, y int, index xy(x, y)) engine=merge union=(t1,t2);
2003-07-03 10:55:36 +02:00
insert into t1 values(1, 2);
insert into t2 values(1, 3);
select * from t3 where x = 1 and y < 5 order by y;
x y
1 2
1 3
select * from t3 where x = 1 and y < 5 order by y desc;
x y
2003-07-04 14:42:57 +02:00
1 3
1 2
2003-07-03 10:55:36 +02:00
drop table t1,t2,t3;
2004-08-27 13:43:01 +02:00
create table t1 (a int);
create table t2 (a int);
insert into t1 values (0);
insert into t2 values (1);
create table t3 engine=merge union=(t1, t2) select * from t1;
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
ERROR HY000: 'test.t3' is not BASE TABLE
2004-08-27 13:43:01 +02:00
create table t3 engine=merge union=(t1, t2) select * from t2;
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
ERROR HY000: 'test.t3' is not BASE TABLE
2004-09-10 12:09:27 +02:00
create table t3 engine=merge union=(t1, t2) select (select max(a) from t2);
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
ERROR HY000: 'test.t3' is not BASE TABLE
2004-08-27 13:43:01 +02:00
drop table t1, t2;
2005-09-23 10:15:11 +02:00
create table t1 (
2005-09-27 15:26:16 +02:00
a double(14,4),
2005-09-23 10:15:11 +02:00
b varchar(10),
index (a,b)
) engine=merge union=(t2,t3);
create table t2 (
2005-09-27 15:26:16 +02:00
a double(14,4),
2005-09-23 10:15:11 +02:00
b varchar(10),
index (a,b)
) engine=myisam;
create table t3 (
2005-09-27 15:26:16 +02:00
a double(14,4),
2005-09-23 10:15:11 +02:00
b varchar(10),
index (a,b)
) engine=myisam;
insert into t2 values ( null, '');
2005-09-29 13:37:30 +02:00
insert into t2 values ( 9999999999.999, '');
2005-09-23 10:15:11 +02:00
insert into t3 select * from t2;
select min(a), max(a) from t1;
min(a) max(a)
2005-09-29 13:37:30 +02:00
9999999999.9990 9999999999.9990
2005-09-23 10:15:11 +02:00
flush tables;
select min(a), max(a) from t1;
min(a) max(a)
2005-09-29 13:37:30 +02:00
9999999999.9990 9999999999.9990
2005-09-23 10:15:11 +02:00
drop table t1, t2, t3;
2004-11-29 04:51:30 +01:00
create table t1 (a int,b int,c int, index (a,b,c));
create table t2 (a int,b int,c int, index (a,b,c));
create table t3 (a int,b int,c int, index (a,b,c))
engine=merge union=(t1 ,t2);
insert into t1 (a,b,c) values (1,1,0),(1,2,0);
insert into t2 (a,b,c) values (1,1,1),(1,2,1);
explain select a,b,c from t3 force index (a) where a=1 order by a,b,c;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t3 ref a a 5 const 2 Using where; Using index
select a,b,c from t3 force index (a) where a=1 order by a,b,c;
a b c
1 1 0
1 1 1
1 2 0
1 2 1
explain select a,b,c from t3 force index (a) where a=1 order by a desc, b desc, c desc;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t3 ref a a 5 const 2 Using where; Using index
select a,b,c from t3 force index (a) where a=1 order by a desc, b desc, c desc;
a b c
1 2 1
1 2 0
1 1 1
1 1 0
2004-12-27 13:05:35 +01:00
show index from t3;
2010-02-20 11:07:32 +01:00
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type Comment Index_comment
t3 1 a 1 a A NULL NULL NULL YES BTREE
t3 1 a 2 b A NULL NULL NULL YES BTREE
t3 1 a 3 c A NULL NULL NULL YES BTREE
2004-11-29 04:51:30 +01:00
drop table t1, t2, t3;
2005-05-18 19:40:39 +02:00
CREATE TABLE t1 ( a INT AUTO_INCREMENT PRIMARY KEY, b VARCHAR(10), UNIQUE (b) )
ENGINE=MyISAM;
CREATE TABLE t2 ( a INT AUTO_INCREMENT, b VARCHAR(10), INDEX (a), INDEX (b) )
ENGINE=MERGE UNION (t1) INSERT_METHOD=FIRST;
INSERT INTO t2 (b) VALUES (1) ON DUPLICATE KEY UPDATE b=2;
INSERT INTO t2 (b) VALUES (1) ON DUPLICATE KEY UPDATE b=3;
SELECT b FROM t2;
b
3
DROP TABLE t1, t2;
2005-12-22 13:48:00 +01:00
create table t1(a int);
create table t2(a int);
insert into t1 values (1);
insert into t2 values (2);
create table t3 (a int) engine=merge union=(t1, t2) insert_method=first;
select * from t3;
a
1
2
insert t2 select * from t2;
select * from t2;
a
2
2
insert t3 select * from t1;
select * from t3;
a
1
1
2
2
insert t1 select * from t3;
select * from t1;
a
1
1
1
1
2
2
select * from t2;
a
2
2
select * from t3;
a
1
1
1
1
2
2
2
2
check table t1, t2;
Table Op Msg_type Msg_text
test.t1 check status OK
test.t2 check status OK
drop table t1, t2, t3;
2006-09-28 19:10:06 +02:00
CREATE TABLE t1(a INT);
INSERT INTO t1 VALUES(2),(1);
CREATE TABLE t2(a INT, KEY(a)) ENGINE=MERGE UNION=(t1);
SELECT * FROM t2 WHERE a=2;
2007-01-31 13:15:20 +01:00
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
2006-09-28 19:10:06 +02:00
DROP TABLE t1, t2;
2006-09-27 15:33:31 +02:00
CREATE TABLE t1(a INT) ENGINE=MEMORY;
CREATE TABLE t2(a INT) ENGINE=MERGE UNION=(t1);
SELECT * FROM t2;
2006-10-06 07:54:47 +02:00
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
2006-09-27 15:33:31 +02:00
DROP TABLE t1, t2;
CREATE TABLE t2(a INT) ENGINE=MERGE UNION=(t3);
SELECT * FROM t2;
2008-10-09 10:55:16 +02:00
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
2006-09-27 15:33:31 +02:00
DROP TABLE t2;
2007-01-31 13:15:20 +01:00
CREATE TABLE t1(a INT, b TEXT);
CREATE TABLE tm1(a TEXT, b INT) ENGINE=MERGE UNION=(t1);
SELECT * FROM tm1;
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
DROP TABLE t1, tm1;
CREATE TABLE t1(a SMALLINT, b SMALLINT);
CREATE TABLE tm1(a INT) ENGINE=MERGE UNION=(t1);
SELECT * FROM tm1;
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
DROP TABLE t1, tm1;
CREATE TABLE t1(a SMALLINT, b SMALLINT, KEY(a, b));
CREATE TABLE tm1(a SMALLINT, b SMALLINT, KEY(a)) ENGINE=MERGE UNION=(t1);
SELECT * FROM tm1;
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
DROP TABLE t1, tm1;
CREATE TABLE t1(a SMALLINT, b SMALLINT, KEY(b));
CREATE TABLE tm1(a SMALLINT, b SMALLINT, KEY(a)) ENGINE=MERGE UNION=(t1);
SELECT * FROM tm1;
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
DROP TABLE t1, tm1;
2007-03-13 15:02:06 +01:00
CREATE TABLE t1(c1 VARCHAR(1));
CREATE TABLE m1 LIKE t1;
ALTER TABLE m1 ENGINE=MERGE UNION=(t1);
SELECT * FROM m1;
c1
DROP TABLE t1, m1;
CREATE TABLE t1(c1 VARCHAR(4), c2 TINYINT, c3 TINYINT, c4 TINYINT,
c5 TINYINT, c6 TINYINT, c7 TINYINT, c8 TINYINT, c9 TINYINT);
CREATE TABLE m1 LIKE t1;
ALTER TABLE m1 ENGINE=MERGE UNION=(t1);
SELECT * FROM m1;
c1 c2 c3 c4 c5 c6 c7 c8 c9
DROP TABLE t1, m1;
2007-04-10 22:40:35 +02:00
CREATE TABLE t1 (a VARCHAR(255) CHARACTER SET latin1 COLLATE latin1_german2_ci,
b INT, INDEX(a,b));
CREATE TABLE t2 LIKE t1;
CREATE TABLE t3 LIKE t1;
ALTER TABLE t3 ENGINE=MERGE UNION=(t1,t2);
INSERT INTO t1 VALUES ('ss',1);
INSERT INTO t2 VALUES ('ss',2),(0xDF,2);
SELECT COUNT(*) FROM t3 WHERE a=0xDF AND b=2;
COUNT(*)
2
DROP TABLE t1,t2,t3;
2006-05-31 02:10:53 +02:00
create table t1 (b bit(1));
create table t2 (b bit(1));
create table tm (b bit(1)) engine = merge union = (t1,t2);
select * from tm;
b
drop table tm, t1, t2;
2006-07-12 02:28:50 +02:00
create table t1 (a int) insert_method = last engine = merge;
insert into t1 values (1);
ERROR HY000: Table 't1' is read only
create table t2 (a int) engine = myisam;
alter table t1 union (t2);
insert into t1 values (1);
alter table t1 insert_method = no;
insert into t1 values (1);
ERROR HY000: Table 't1' is read only
drop table t2;
drop table t1;
2007-06-06 01:42:41 +02:00
CREATE TABLE tm1(a INT) ENGINE=MERGE UNION=(t1, t2);
SELECT * FROM tm1;
2008-10-09 10:55:16 +02:00
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
2007-06-06 01:42:41 +02:00
CHECK TABLE tm1;
Table Op Msg_type Msg_text
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
test.tm1 check Error Table 'test.t1' doesn't exist
2008-10-09 10:55:16 +02:00
test.tm1 check Error Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
2007-06-06 01:42:41 +02:00
test.tm1 check error Corrupt
CREATE TABLE t1(a INT);
SELECT * FROM tm1;
2008-10-09 10:55:16 +02:00
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
2007-06-06 01:42:41 +02:00
CHECK TABLE tm1;
Table Op Msg_type Msg_text
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
test.tm1 check Error Table 'test.t2' doesn't exist
2008-10-09 10:55:16 +02:00
test.tm1 check Error Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
2007-06-06 01:42:41 +02:00
test.tm1 check error Corrupt
CREATE TABLE t2(a BLOB);
SELECT * FROM tm1;
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
CHECK TABLE tm1;
Table Op Msg_type Msg_text
2009-09-10 11:18:29 +02:00
test.tm1 check Warning Table 'test.t2' is differently defined or of non-MyISAM type or doesn't exist
2007-06-06 01:42:41 +02:00
test.tm1 check Error Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
test.tm1 check error Corrupt
ALTER TABLE t2 MODIFY a INT;
SELECT * FROM tm1;
a
CHECK TABLE tm1;
Table Op Msg_type Msg_text
test.tm1 check status OK
DROP TABLE tm1, t1, t2;
2007-10-09 13:10:51 +02:00
CREATE TABLE t1(c1 INT);
CREATE TABLE t2 (c1 INT) ENGINE=MERGE UNION=(t1) INSERT_METHOD=FIRST;
CREATE TABLE IF NOT EXISTS t1 SELECT * FROM t2;
ERROR HY000: You can't specify target table 't1' for update in FROM clause
DROP TABLE t1, t2;
2007-11-26 16:58:54 +01:00
CREATE TABLE t1 (id INT NOT NULL, ref INT NOT NULL, INDEX (id)) ENGINE=MyISAM;
CREATE TABLE t2 LIKE t1;
INSERT INTO t2 (id, ref) VALUES (1,3), (2,1), (3,2), (4,5), (4,4);
INSERT INTO t1 SELECT * FROM t2;
INSERT INTO t1 SELECT * FROM t2;
CREATE TABLE t3 (id INT NOT NULL, ref INT NOT NULL, INDEX (id)) ENGINE=MERGE
UNION(t1);
SELECT * FROM t3 AS a INNER JOIN t3 AS b USING (id) WHERE a.ref < b.ref;
id ref ref
4 4 5
4 4 5
4 4 5
4 4 5
SELECT * FROM t3;
id ref
1 3
2 1
3 2
4 5
4 4
1 3
2 1
3 2
4 5
4 4
DELETE FROM a USING t3 AS a INNER JOIN t3 AS b USING (id) WHERE a.ref < b.ref;
SELECT * FROM t3;
id ref
1 3
2 1
3 2
4 5
1 3
2 1
3 2
4 5
DROP TABLE t1, t2, t3;
2008-03-14 16:38:22 +01:00
CREATE TABLE t1(a INT);
CREATE TABLE m1(a INT) ENGINE=MERGE;
SHOW CREATE TABLE m1;
Table Create Table
m1 CREATE TABLE `m1` (
2008-03-14 21:37:19 +01:00
`a` int(11) DEFAULT NULL
2008-03-14 16:38:22 +01:00
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1
DROP TABLE m1;
CREATE TABLE m1(a INT) ENGINE=MERGE UNION=();
SHOW CREATE TABLE m1;
Table Create Table
m1 CREATE TABLE `m1` (
2008-03-14 21:37:19 +01:00
`a` int(11) DEFAULT NULL
2008-03-14 16:38:22 +01:00
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1
ALTER TABLE m1 UNION=(t1);
ALTER TABLE m1 UNION=();
SHOW CREATE TABLE m1;
Table Create Table
m1 CREATE TABLE `m1` (
2008-03-14 21:37:19 +01:00
`a` int(11) DEFAULT NULL
2008-03-14 16:38:22 +01:00
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1
DROP TABLE t1, m1;
2010-05-31 15:38:02 +02:00
CREATE TABLE t1(a INT, KEY(a)) ENGINE=merge;
SELECT MAX(a) FROM t1;
MAX(a)
NULL
DROP TABLE t1;
2009-02-04 12:46:23 +01:00
CREATE TABLE t1(a INT);
CREATE TABLE t2(a VARCHAR(10));
CREATE TABLE m1(a INT) ENGINE=MERGE UNION=(t1, t2);
CREATE TABLE m2(a INT) ENGINE=MERGE UNION=(t1);
SELECT * FROM t1;
a
SELECT * FROM m1;
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
SELECT * FROM m2;
a
DROP TABLE t1, t2, m1, m2;
2006-07-12 02:28:50 +02:00
End of 5.0 tests
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
create table t1 (c1 int, index(c1));
create table t2 (c1 int, index(c1)) engine=merge union=(t1);
insert into t1 values (1);
flush tables;
select * from t2;
c1
1
flush tables;
truncate table t1;
insert into t1 values (1);
flush tables;
select * from t2;
c1
1
truncate table t1;
insert into t1 values (1);
drop table t1,t2;
#
# Extra tests for TRUNCATE.
#
# Truncate MERGE table.
CREATE TABLE t1 (c1 INT, INDEX(c1));
CREATE TABLE t2 (c1 INT, INDEX(c1));
CREATE TABLE t3 (c1 INT, INDEX(c1)) ENGINE=MRG_MYISAM UNION=(t1,t2);
INSERT INTO t1 VALUES (1);
INSERT INTO t2 VALUES (2);
SELECT * FROM t3;
c1
1
2
TRUNCATE TABLE t3;
SELECT * FROM t3;
c1
#
# Truncate child table.
INSERT INTO t1 VALUES (1);
INSERT INTO t2 VALUES (2);
TRUNCATE TABLE t1;
SELECT * FROM t3;
c1
2
#
# Truncate MERGE table under locked tables.
LOCK TABLE t1 WRITE, t2 WRITE, t3 WRITE;
INSERT INTO t1 VALUES (1);
TRUNCATE TABLE t3;
SELECT * FROM t3;
c1
2009-12-11 13:24:23 +01:00
UNLOCK TABLES;
SELECT * FROM t1;
c1
SELECT * FROM t2;
c1
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
#
# Truncate child table under locked tables.
2009-12-11 13:24:23 +01:00
LOCK TABLE t1 WRITE, t2 WRITE, t3 WRITE;
INSERT INTO t1 VALUES (1);
INSERT INTO t2 VALUES (2);
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
TRUNCATE TABLE t1;
SELECT * FROM t3;
c1
2
UNLOCK TABLES;
DROP TABLE t1, t2, t3;
#
# Truncate temporary MERGE table.
CREATE TEMPORARY TABLE t1 (c1 INT, INDEX(c1));
CREATE TEMPORARY TABLE t2 (c1 INT, INDEX(c1));
CREATE TEMPORARY TABLE t3 (c1 INT, INDEX(c1)) ENGINE=MRG_MYISAM UNION=(t1,t2);
INSERT INTO t1 VALUES (1);
INSERT INTO t2 VALUES (2);
SELECT * FROM t3;
c1
1
2
TRUNCATE TABLE t3;
SELECT * FROM t3;
c1
#
# Truncate temporary child table.
INSERT INTO t1 VALUES (1);
INSERT INTO t2 VALUES (2);
TRUNCATE TABLE t1;
SELECT * FROM t3;
c1
2
#
# Truncate temporary MERGE table under locked tables.
INSERT INTO t1 VALUES (1);
CREATE TABLE t4 (c1 INT, INDEX(c1));
LOCK TABLE t4 WRITE;
TRUNCATE TABLE t3;
SELECT * FROM t3;
c1
2009-12-11 13:24:23 +01:00
SELECT * FROM t1;
c1
SELECT * FROM t2;
c1
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
#
# Truncate temporary child table under locked tables.
2009-12-11 13:24:23 +01:00
INSERT INTO t1 VALUES (1);
INSERT INTO t2 VALUES (2);
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
TRUNCATE TABLE t1;
SELECT * FROM t3;
c1
2009-12-11 13:24:23 +01:00
2
SELECT * FROM t1;
c1
SELECT * FROM t2;
c1
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
2
UNLOCK TABLES;
DROP TABLE t1, t2, t3, t4;
CREATE TABLE t1 (c1 INT) ENGINE= MyISAM;
CREATE TABLE t2 (c1 INT) ENGINE= MRG_MYISAM UNION= (t1) INSERT_METHOD= LAST;
REPAIR TABLE t1;
INSERT INTO t2 VALUES (1);
Table Op Msg_type Msg_text
test.t1 repair status OK
DROP TABLE t1, t2;
CREATE TABLE t1 (c1 INT) ENGINE= MyISAM;
CREATE TABLE t2 (c1 INT) ENGINE= MRG_MYISAM UNION= (t1) INSERT_METHOD= LAST;
LOCK TABLE t1 WRITE;
INSERT INTO t2 VALUES (1);
REPAIR TABLE t1;
Table Op Msg_type Msg_text
test.t1 repair status OK
UNLOCK TABLES;
DROP TABLE t1, t2;
CREATE TABLE t1 (c1 INT) ENGINE= MyISAM;
LOCK TABLE t1 WRITE;
INSERT INTO t1 VALUES (1);
FLUSH TABLES;
FLUSH TABLES;
SELECT * FROM t1;
c1
UNLOCK TABLES;
DROP TABLE t1;
#
# Extra tests for Bug#26379 - Combination of FLUSH TABLE and
# REPAIR TABLE corrupts a MERGE table
#
# CREATE ... SELECT is disabled for MERGE tables.
#
CREATE TABLE t1(c1 INT);
INSERT INTO t1 VALUES (1);
CREATE TABLE t2 (c1 INT) ENGINE=MRG_MYISAM UNION=(t1) INSERT_METHOD=LAST;
CREATE TABLE t3 ENGINE=MRG_MYISAM INSERT_METHOD=LAST SELECT * FROM t2;
ERROR HY000: Table 't3' is read only
SHOW CREATE TABLE t3;
ERROR 42S02: Table 'test.t3' doesn't exist
CREATE TABLE t3 ENGINE=MRG_MYISAM UNION=(t1) INSERT_METHOD=LAST
SELECT * FROM t2;
ERROR HY000: 'test.t3' is not BASE TABLE
SHOW CREATE TABLE t3;
ERROR 42S02: Table 'test.t3' doesn't exist
DROP TABLE t1, t2;
#
2009-12-10 11:53:20 +01:00
# Bug#37371 "CREATE TABLE LIKE merge loses UNION parameter"
# Demonstrate that this is no longer the case.
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
#
# 1. Create like.
CREATE TABLE t1 (c1 INT);
CREATE TABLE t2 (c1 INT);
CREATE TABLE t3 (c1 INT) ENGINE=MRG_MYISAM UNION=(t1,t2)
INSERT_METHOD=LAST;
INSERT INTO t1 VALUES (1);
INSERT INTO t2 VALUES (2);
INSERT INTO t3 VALUES (3);
CREATE TABLE t4 LIKE t3;
SHOW CREATE TABLE t4;
Table Create Table
t4 CREATE TABLE `t4` (
`c1` int(11) DEFAULT NULL
2009-12-10 11:53:20 +01:00
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 INSERT_METHOD=LAST UNION=(`t1`,`t2`)
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
INSERT INTO t4 VALUES (4);
DROP TABLE t4;
#
# 1. Create like with locked tables.
LOCK TABLES t3 WRITE, t2 WRITE, t1 WRITE;
CREATE TABLE t4 LIKE t3;
2009-12-10 11:53:20 +01:00
ERROR HY000: Table 't4' was not locked with LOCK TABLES
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
SHOW CREATE TABLE t4;
ERROR HY000: Table 't4' was not locked with LOCK TABLES
INSERT INTO t4 VALUES (4);
ERROR HY000: Table 't4' was not locked with LOCK TABLES
2010-06-25 17:32:59 +02:00
# Temporary tables can be created in spite of LOCK TABLES.
# If the temporary MERGE table uses the locked children only,
# it can even be used.
2009-12-10 11:53:20 +01:00
CREATE TEMPORARY TABLE t4 LIKE t3;
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
SHOW CREATE TABLE t4;
2009-12-10 11:53:20 +01:00
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
INSERT INTO t4 VALUES (4);
2009-12-10 11:53:20 +01:00
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
UNLOCK TABLES;
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
INSERT INTO t4 VALUES (4);
2009-12-10 11:53:20 +01:00
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
DROP TABLE t4;
#
# Rename child.
#
# 1. Normal rename of non-MERGE table.
CREATE TABLE t4 (c1 INT);
INSERT INTO t4 VALUES (4);
SELECT * FROM t4 ORDER BY c1;
c1
4
RENAME TABLE t4 TO t5;
SELECT * FROM t5 ORDER BY c1;
c1
4
RENAME TABLE t5 TO t4;
SELECT * FROM t4 ORDER BY c1;
c1
4
DROP TABLE t4;
#
# 2. Normal rename.
SELECT * FROM t3 ORDER BY c1;
c1
1
2
3
2009-12-10 11:53:20 +01:00
4
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
RENAME TABLE t2 TO t5;
SELECT * FROM t3 ORDER BY c1;
2008-10-09 10:55:16 +02:00
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
RENAME TABLE t5 TO t2;
SELECT * FROM t3 ORDER BY c1;
c1
1
2
3
2009-12-10 11:53:20 +01:00
4
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
#
# 3. Normal rename with locked tables.
LOCK TABLES t1 WRITE, t2 WRITE, t3 WRITE;
SELECT * FROM t3 ORDER BY c1;
c1
1
2
3
2009-12-10 11:53:20 +01:00
4
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
RENAME TABLE t2 TO t5;
ERROR HY000: Can't execute the given command because you have active locked tables or an active transaction
SELECT * FROM t3 ORDER BY c1;
c1
1
2
3
2009-12-10 11:53:20 +01:00
4
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
RENAME TABLE t5 TO t2;
ERROR HY000: Can't execute the given command because you have active locked tables or an active transaction
SELECT * FROM t3 ORDER BY c1;
c1
1
2
3
2009-12-10 11:53:20 +01:00
4
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
UNLOCK TABLES;
#
# 4. Alter table rename.
ALTER TABLE t2 RENAME TO t5;
SELECT * FROM t3 ORDER BY c1;
2008-10-09 10:55:16 +02:00
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
ALTER TABLE t5 RENAME TO t2;
SELECT * FROM t3 ORDER BY c1;
c1
1
2
3
2009-12-10 11:53:20 +01:00
4
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
#
# 5. Alter table rename with locked tables.
LOCK TABLES t1 WRITE, t2 WRITE, t3 WRITE;
ALTER TABLE t2 RENAME TO t5;
SELECT * FROM t3 ORDER BY c1;
2009-12-03 00:09:22 +01:00
ERROR HY000: Table 't2' was not locked with LOCK TABLES
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
ALTER TABLE t5 RENAME TO t2;
ERROR HY000: Table 't5' was not locked with LOCK TABLES
UNLOCK TABLES;
ALTER TABLE t5 RENAME TO t2;
SELECT * FROM t3 ORDER BY c1;
c1
1
2
3
2009-12-10 11:53:20 +01:00
4
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
#
# Rename parent.
#
# 1. Normal rename with locked tables.
LOCK TABLES t1 WRITE, t2 WRITE, t3 WRITE;
SELECT * FROM t3 ORDER BY c1;
c1
1
2
3
2009-12-10 11:53:20 +01:00
4
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
RENAME TABLE t3 TO t5;
ERROR HY000: Can't execute the given command because you have active locked tables or an active transaction
SELECT * FROM t3 ORDER BY c1;
c1
1
2
3
2009-12-10 11:53:20 +01:00
4
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
RENAME TABLE t5 TO t3;
ERROR HY000: Can't execute the given command because you have active locked tables or an active transaction
SELECT * FROM t3 ORDER BY c1;
c1
1
2
3
2009-12-10 11:53:20 +01:00
4
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
#
# 5. Alter table rename with locked tables.
ALTER TABLE t3 RENAME TO t5;
SELECT * FROM t5 ORDER BY c1;
ERROR HY000: Table 't5' was not locked with LOCK TABLES
ALTER TABLE t5 RENAME TO t3;
ERROR HY000: Table 't5' was not locked with LOCK TABLES
UNLOCK TABLES;
ALTER TABLE t5 RENAME TO t3;
SELECT * FROM t3 ORDER BY c1;
c1
1
2
3
2009-12-10 11:53:20 +01:00
4
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
DROP TABLE t1, t2, t3;
#
# Drop locked tables.
#
# 1. Drop parent.
CREATE TABLE t1 (c1 INT, INDEX(c1));
CREATE TABLE t2 (c1 INT, INDEX(c1)) ENGINE=MRG_MYISAM UNION=(t1)
INSERT_METHOD=LAST;
LOCK TABLES t1 WRITE, t2 WRITE;
INSERT INTO t1 VALUES (1);
DROP TABLE t2;
SELECT * FROM t2;
ERROR HY000: Table 't2' was not locked with LOCK TABLES
SELECT * FROM t1;
c1
1
UNLOCK TABLES;
# 2. Drop child.
CREATE TABLE t2 (c1 INT, INDEX(c1)) ENGINE=MRG_MYISAM UNION=(t1)
INSERT_METHOD=LAST;
LOCK TABLES t1 WRITE, t2 WRITE;
INSERT INTO t1 VALUES (1);
DROP TABLE t1;
SELECT * FROM t2;
2009-12-03 00:09:22 +01:00
ERROR HY000: Table 't1' was not locked with LOCK TABLES
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
SELECT * FROM t1;
2009-12-03 00:09:22 +01:00
ERROR HY000: Table 't1' was not locked with LOCK TABLES
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
UNLOCK TABLES;
DROP TABLE t2;
#
# ALTER TABLE. Change child list.
#
CREATE TABLE t1 (c1 INT, INDEX(c1));
CREATE TABLE t2 (c1 INT, INDEX(c1));
CREATE TABLE t3 (c1 INT, INDEX(c1));
INSERT INTO t1 VALUES (1);
INSERT INTO t2 VALUES (2);
INSERT INTO t3 VALUES (3);
CREATE TABLE t4 (c1 INT, INDEX(c1)) ENGINE=MRG_MYISAM UNION=(t3,t2)
INSERT_METHOD=LAST;
# Shrink child list.
ALTER TABLE t4 UNION=(t3);
SHOW CREATE TABLE t4;
Table Create Table
t4 CREATE TABLE `t4` (
`c1` int(11) DEFAULT NULL,
KEY `c1` (`c1`)
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 INSERT_METHOD=LAST UNION=(`t3`)
SELECT * FROM t4 ORDER BY c1;
c1
3
# Extend child list.
ALTER TABLE t4 UNION=(t3,t2);
SHOW CREATE TABLE t4;
Table Create Table
t4 CREATE TABLE `t4` (
`c1` int(11) DEFAULT NULL,
KEY `c1` (`c1`)
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 INSERT_METHOD=LAST UNION=(`t3`,`t2`)
SELECT * FROM t4 ORDER BY c1;
c1
2
3
#
# ALTER TABLE under LOCK TABLES. Change child list.
#
LOCK TABLES t4 WRITE, t3 WRITE, t2 WRITE;
# Shrink child list.
ALTER TABLE t4 UNION=(t3);
ERROR HY000: Can't execute the given command because you have active locked tables or an active transaction
# Extend child list within locked tables.
ALTER TABLE t4 UNION=(t3,t2);
ERROR HY000: Can't execute the given command because you have active locked tables or an active transaction
# Extend child list beyond locked tables.
ALTER TABLE t4 UNION=(t3,t2,t1);
ERROR HY000: Can't execute the given command because you have active locked tables or an active transaction
SHOW CREATE TABLE t4;
Table Create Table
t4 CREATE TABLE `t4` (
`c1` int(11) DEFAULT NULL,
KEY `c1` (`c1`)
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 INSERT_METHOD=LAST UNION=(`t3`,`t2`)
SELECT * FROM t4 ORDER BY c1;
c1
2
3
UNLOCK TABLES;
DROP TABLE t4;
#
# ALTER TABLE under LOCK TABLES. Grave change, table re-creation.
#
CREATE TABLE t4 (c1 INT, INDEX(c1)) ENGINE=MRG_MYISAM UNION=(t1,t2,t3)
INSERT_METHOD=LAST;
# Lock parent first and then children.
LOCK TABLES t4 WRITE, t3 WRITE, t2 WRITE, t1 WRITE;
ALTER TABLE t4 DROP INDEX c1, ADD UNIQUE INDEX (c1);
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
ALTER TABLE t2 DROP INDEX c1, ADD UNIQUE INDEX (c1);
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
UNLOCK TABLES;
# Lock children first and then parent.
LOCK TABLES t1 WRITE, t2 WRITE, t3 WRITE, t4 WRITE;
ALTER TABLE t4 DROP INDEX c1, ADD UNIQUE INDEX (c1);
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
ALTER TABLE t2 DROP INDEX c1, ADD UNIQUE INDEX (c1);
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
UNLOCK TABLES;
# Lock parent between children.
LOCK TABLES t3 WRITE, t2 WRITE, t4 WRITE, t1 WRITE;
ALTER TABLE t4 DROP INDEX c1, ADD UNIQUE INDEX (c1);
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
ALTER TABLE t2 DROP INDEX c1, ADD UNIQUE INDEX (c1);
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
UNLOCK TABLES;
DROP TABLE t1, t2, t3, t4;
#
# ALTER TABLE under LOCK TABLES. Simple change, no re-creation.
#
CREATE TABLE t1 (c1 INT);
CREATE TABLE t2 (c1 INT);
CREATE TABLE t3 (c1 INT);
CREATE TABLE t4 (c1 INT) ENGINE=MRG_MYISAM UNION=(t1,t2,t3)
INSERT_METHOD=LAST;
INSERT INTO t1 VALUES (1);
INSERT INTO t2 VALUES (2);
INSERT INTO t3 VALUES (3);
# Lock parent first and then children.
LOCK TABLES t4 WRITE, t3 WRITE, t2 WRITE, t1 WRITE;
ALTER TABLE t4 ALTER COLUMN c1 SET DEFAULT 44;
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
ALTER TABLE t2 ALTER COLUMN c1 SET DEFAULT 22;
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
UNLOCK TABLES;
# Lock children first and then parent.
LOCK TABLES t1 WRITE, t2 WRITE, t3 WRITE, t4 WRITE;
ALTER TABLE t4 ALTER COLUMN c1 SET DEFAULT 44;
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
ALTER TABLE t2 ALTER COLUMN c1 SET DEFAULT 22;
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
UNLOCK TABLES;
# Lock parent between children.
LOCK TABLES t3 WRITE, t2 WRITE, t4 WRITE, t1 WRITE;
ALTER TABLE t4 ALTER COLUMN c1 SET DEFAULT 44;
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
ALTER TABLE t2 ALTER COLUMN c1 SET DEFAULT 22;
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
UNLOCK TABLES;
#
# FLUSH TABLE under LOCK TABLES.
#
# Lock parent first and then children.
LOCK TABLES t4 WRITE, t3 WRITE, t2 WRITE, t1 WRITE;
FLUSH TABLE t4;
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
FLUSH TABLE t2;
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
FLUSH TABLES;
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
UNLOCK TABLES;
# Lock children first and then parent.
LOCK TABLES t1 WRITE, t2 WRITE, t3 WRITE, t4 WRITE;
FLUSH TABLE t4;
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
FLUSH TABLE t2;
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
FLUSH TABLES;
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
UNLOCK TABLES;
# Lock parent between children.
LOCK TABLES t3 WRITE, t2 WRITE, t4 WRITE, t1 WRITE;
FLUSH TABLE t4;
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
FLUSH TABLE t2;
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
FLUSH TABLES;
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
UNLOCK TABLES;
#
# Triggers
#
# Trigger on parent
DELETE FROM t4 WHERE c1 = 4;
CREATE TRIGGER t4_ai AFTER INSERT ON t4 FOR EACH ROW SET @a=1;
SET @a=0;
INSERT INTO t4 VALUES (4);
SELECT @a;
@a
1
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
4
DROP TRIGGER t4_ai;
# Trigger on parent under LOCK TABLES
LOCK TABLES t3 WRITE, t2 WRITE, t4 WRITE, t1 WRITE;
CREATE TRIGGER t4_ai AFTER INSERT ON t4 FOR EACH ROW SET @a=1;
SET @a=0;
INSERT INTO t4 VALUES (4);
SELECT @a;
@a
1
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
4
4
DROP TRIGGER t4_ai;
UNLOCK TABLES;
#
# Trigger on child
DELETE FROM t4 WHERE c1 = 4;
CREATE TRIGGER t3_ai AFTER INSERT ON t3 FOR EACH ROW SET @a=1;
SET @a=0;
INSERT INTO t4 VALUES (4);
SELECT @a;
@a
0
INSERT INTO t3 VALUES (33);
SELECT @a;
@a
1
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
4
33
DROP TRIGGER t3_ai;
# Trigger on child under LOCK TABLES
LOCK TABLES t3 WRITE, t2 WRITE, t4 WRITE, t1 WRITE;
CREATE TRIGGER t3_ai AFTER INSERT ON t3 FOR EACH ROW SET @a=1;
SET @a=0;
INSERT INTO t4 VALUES (4);
SELECT @a;
@a
0
INSERT INTO t3 VALUES (33);
SELECT @a;
@a
1
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
4
4
33
33
DELETE FROM t4 WHERE c1 = 33;
DROP TRIGGER t3_ai;
2010-06-25 17:32:59 +02:00
UNLOCK TABLES;
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
#
# Trigger with table use on child
DELETE FROM t4 WHERE c1 = 4;
CREATE TRIGGER t3_ai AFTER INSERT ON t3 FOR EACH ROW INSERT INTO t2 VALUES(22);
INSERT INTO t4 VALUES (4);
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
4
INSERT INTO t3 VALUES (33);
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
4
22
33
DELETE FROM t4 WHERE c1 = 22;
DELETE FROM t4 WHERE c1 = 33;
DROP TRIGGER t3_ai;
# Trigger with table use on child under LOCK TABLES
LOCK TABLES t3 WRITE, t2 WRITE, t4 WRITE, t1 WRITE;
CREATE TRIGGER t3_ai AFTER INSERT ON t3 FOR EACH ROW INSERT INTO t2 VALUES(22);
INSERT INTO t4 VALUES (4);
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
4
4
INSERT INTO t3 VALUES (33);
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
4
4
22
33
DROP TRIGGER t3_ai;
DELETE FROM t4 WHERE c1 = 22;
DELETE FROM t4 WHERE c1 = 33;
UNLOCK TABLES;
#
# Repair
#
REPAIR TABLE t4;
Table Op Msg_type Msg_text
test.t4 repair note The storage engine for the table doesn't support repair
REPAIR TABLE t2;
Table Op Msg_type Msg_text
test.t2 repair status OK
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
4
4
LOCK TABLES t3 WRITE, t2 WRITE, t4 WRITE, t1 WRITE;
REPAIR TABLE t4;
Table Op Msg_type Msg_text
test.t4 repair note The storage engine for the table doesn't support repair
REPAIR TABLE t2;
Table Op Msg_type Msg_text
test.t2 repair status OK
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
4
4
UNLOCK TABLES;
#
# Optimize
#
OPTIMIZE TABLE t4;
Table Op Msg_type Msg_text
test.t4 optimize note The storage engine for the table doesn't support optimize
OPTIMIZE TABLE t2;
Table Op Msg_type Msg_text
test.t2 optimize status OK
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
4
4
LOCK TABLES t3 WRITE, t2 WRITE, t4 WRITE, t1 WRITE;
OPTIMIZE TABLE t4;
Table Op Msg_type Msg_text
test.t4 optimize note The storage engine for the table doesn't support optimize
OPTIMIZE TABLE t2;
Table Op Msg_type Msg_text
test.t2 optimize status Table is already up to date
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
4
4
UNLOCK TABLES;
#
# Checksum
#
CHECKSUM TABLE t4;
Table Checksum
test.t4 46622073
CHECKSUM TABLE t2;
Table Checksum
test.t2 3700403066
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
4
4
LOCK TABLES t3 WRITE, t2 WRITE, t4 WRITE, t1 WRITE;
CHECKSUM TABLE t4;
Table Checksum
test.t4 46622073
CHECKSUM TABLE t2;
Table Checksum
test.t2 3700403066
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
4
4
UNLOCK TABLES;
#
# Insert delayed
#
INSERT DELAYED INTO t4 VALUES(44);
DELETE FROM t4 WHERE c1 = 44;
INSERT DELAYED INTO t3 VALUES(33);
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
4
4
33
LOCK TABLES t3 WRITE, t2 WRITE, t4 WRITE, t1 WRITE;
INSERT DELAYED INTO t4 VALUES(444);
Got one of the listed errors
INSERT DELAYED INTO t3 VALUES(333);
Got one of the listed errors
SELECT * FROM t4 ORDER BY c1;
c1
1
2
3
4
4
33
UNLOCK TABLES;
DROP TABLE t1, t2, t3, t4;
#
# Recursive inclusion of merge tables in their union clauses.
#
CREATE TABLE t1 (c1 INT, INDEX(c1));
CREATE TABLE t2 (c1 INT, INDEX(c1)) ENGINE=MRG_MYISAM UNION=(t1)
INSERT_METHOD=LAST;
CREATE TABLE t3 (c1 INT, INDEX(c1)) ENGINE=MRG_MYISAM UNION=(t2,t1)
INSERT_METHOD=LAST;
ALTER TABLE t2 UNION=(t3,t1);
SELECT * FROM t2;
ERROR HY000: Table 't3' is differently defined or of non-MyISAM type or doesn't exist
DROP TABLE t1, t2, t3;
2010-06-25 17:32:59 +02:00
CREATE TABLE t1 (c1 INT) ENGINE=MyISAM;
CREATE TABLE t2 (c1 INT) ENGINE=MyISAM;
CREATE TABLE t3 (c1 INT) ENGINE=MRG_MYISAM UNION=(t1,t2);
Bug#26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Bug 25038 - Waiting TRUNCATE
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Bug 19627 - temporary merge table locking
Bug 27660 - Falcon: merge table possible
Bug 30273 - merge tables: Can't lock file (errno: 155)
The problems were:
Bug 26379 - Combination of FLUSH TABLE and REPAIR TABLE
corrupts a MERGE table
1. A thread trying to lock a MERGE table performs busy waiting while
REPAIR TABLE or a similar table administration task is ongoing on
one or more of its MyISAM tables.
2. A thread trying to lock a MERGE table performs busy waiting until all
threads that did REPAIR TABLE or similar table administration tasks
on one or more of its MyISAM tables in LOCK TABLES segments do UNLOCK
TABLES. The difference against problem #1 is that the busy waiting
takes place *after* the administration task. It is terminated by
UNLOCK TABLES only.
3. Two FLUSH TABLES within a LOCK TABLES segment can invalidate the
lock. This does *not* require a MERGE table. The first FLUSH TABLES
can be replaced by any statement that requires other threads to
reopen the table. In 5.0 and 5.1 a single FLUSH TABLES can provoke
the problem.
Bug 26867 - LOCK TABLES + REPAIR + merge table result in
memory/cpu hogging
Trying DML on a MERGE table, which has a child locked and
repaired by another thread, made an infinite loop in the server.
Bug 26377 - Deadlock with MERGE and FLUSH TABLE
Locking a MERGE table and its children in parent-child order
and flushing the child deadlocked the server.
Bug 25038 - Waiting TRUNCATE
Truncating a MERGE child, while the MERGE table was in use,
let the truncate fail instead of waiting for the table to
become free.
Bug 25700 - merge base tables get corrupted by
optimize/analyze/repair table
Repairing a child of an open MERGE table corrupted the child.
It was necessary to FLUSH the child first.
Bug 30275 - Merge tables: flush tables or unlock tables
causes server to crash
Flushing and optimizing locked MERGE children crashed the server.
Bug 19627 - temporary merge table locking
Use of a temporary MERGE table with non-temporary children
could corrupt the children.
Temporary tables are never locked. So we do now prohibit
non-temporary chidlren of a temporary MERGE table.
Bug 27660 - Falcon: merge table possible
It was possible to create a MERGE table with non-MyISAM children.
Bug 30273 - merge tables: Can't lock file (errno: 155)
This was a Windows-only bug. Table administration statements
sometimes failed with "Can't lock file (errno: 155)".
These bugs are fixed by a new implementation of MERGE table open.
When opening a MERGE table in open_tables() we do now add the
child tables to the list of tables to be opened by open_tables()
(the "query_list"). The children are not opened in the handler at
this stage.
After opening the parent, open_tables() opens each child from the
now extended query_list. When the last child is opened, we remove
the children from the query_list again and attach the children to
the parent. This behaves similar to the old open. However it does
not open the MyISAM tables directly, but grabs them from the already
open children.
When closing a MERGE table in close_thread_table() we detach the
children only. Closing of the children is done implicitly because
they are in thd->open_tables.
For more detail see the comment at the top of ha_myisammrg.cc.
Changed from open_ltable() to open_and_lock_tables() in all places
that can be relevant for MERGE tables. The latter can handle tables
added to the list on the fly. When open_ltable() was used in a loop
over a list of tables, the list must be temporarily terminated
after every table for open_and_lock_tables().
table_list->required_type is set to FRMTYPE_TABLE to avoid open of
special tables. Handling of derived tables is suppressed.
These details are handled by the new function
open_n_lock_single_table(), which has nearly the same signature as
open_ltable() and can replace it in most cases.
In reopen_tables() some of the tables open by a thread can be
closed and reopened. When a MERGE child is affected, the parent
must be closed and reopened too. Closing of the parent is forced
before the first child is closed. Reopen happens in the order of
thd->open_tables. MERGE parents do not attach their children
automatically at open. This is done after all tables are reopened.
So all children are open when attaching them.
Special lock handling like mysql_lock_abort() or mysql_lock_remove()
needs to be suppressed for MERGE children or forwarded to the parent.
This depends on the situation. In loops over all open tables one
suppresses child lock handling. When a single table is touched,
forwarding is done.
Behavioral changes:
===================
This patch changes the behavior of temporary MERGE tables.
Temporary MERGE must have temporary children.
The old behavior was wrong. A temporary table is not locked. Hence
even non-temporary children were not locked. See
Bug 19627 - temporary merge table locking.
You cannot change the union list of a non-temporary MERGE table
when LOCK TABLES is in effect. The following does *not* work:
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ...;
LOCK TABLES t1 WRITE, t2 WRITE, m1 WRITE;
ALTER TABLE m1 ... UNION=(t1,t2) ...;
However, you can do this with a temporary MERGE table.
You cannot create a MERGE table with CREATE ... SELECT, neither
as a temporary MERGE table, nor as a non-temporary MERGE table.
CREATE TABLE m1 ... ENGINE=MRG_MYISAM ... SELECT ...;
Gives error message: table is not BASE TABLE.
2007-11-15 20:25:43 +01:00
INSERT INTO t1 VALUES (1);
INSERT INTO t2 VALUES (2);
SELECT * FROM t3;
c1
1
2
TRUNCATE TABLE t1;
SELECT * FROM t3;
c1
2
DROP TABLE t1, t2, t3;
CREATE TABLE t1 (id INTEGER, grp TINYINT, id_rev INTEGER);
SET @rnd_max= 2147483647;
SET @rnd= RAND();
SET @id = CAST(@rnd * @rnd_max AS UNSIGNED);
SET @id_rev= @rnd_max - @id;
SET @grp= CAST(127.0 * @rnd AS UNSIGNED);
INSERT INTO t1 (id, grp, id_rev) VALUES (@id, @grp, @id_rev);
SET @rnd= RAND();
SET @id = CAST(@rnd * @rnd_max AS UNSIGNED);
SET @id_rev= @rnd_max - @id;
SET @grp= CAST(127.0 * @rnd AS UNSIGNED);
INSERT INTO t1 (id, grp, id_rev) VALUES (@id, @grp, @id_rev);
SET @rnd= RAND();
SET @id = CAST(@rnd * @rnd_max AS UNSIGNED);
SET @id_rev= @rnd_max - @id;
SET @grp= CAST(127.0 * @rnd AS UNSIGNED);
INSERT INTO t1 (id, grp, id_rev) VALUES (@id, @grp, @id_rev);
SET @rnd= RAND();
SET @id = CAST(@rnd * @rnd_max AS UNSIGNED);
SET @id_rev= @rnd_max - @id;
SET @grp= CAST(127.0 * @rnd AS UNSIGNED);
INSERT INTO t1 (id, grp, id_rev) VALUES (@id, @grp, @id_rev);
SET @rnd= RAND();
SET @id = CAST(@rnd * @rnd_max AS UNSIGNED);
SET @id_rev= @rnd_max - @id;
SET @grp= CAST(127.0 * @rnd AS UNSIGNED);
INSERT INTO t1 (id, grp, id_rev) VALUES (@id, @grp, @id_rev);
SET @rnd= RAND();
SET @id = CAST(@rnd * @rnd_max AS UNSIGNED);
SET @id_rev= @rnd_max - @id;
SET @grp= CAST(127.0 * @rnd AS UNSIGNED);
INSERT INTO t1 (id, grp, id_rev) VALUES (@id, @grp, @id_rev);
SET @rnd= RAND();
SET @id = CAST(@rnd * @rnd_max AS UNSIGNED);
SET @id_rev= @rnd_max - @id;
SET @grp= CAST(127.0 * @rnd AS UNSIGNED);
INSERT INTO t1 (id, grp, id_rev) VALUES (@id, @grp, @id_rev);
SET @rnd= RAND();
SET @id = CAST(@rnd * @rnd_max AS UNSIGNED);
SET @id_rev= @rnd_max - @id;
SET @grp= CAST(127.0 * @rnd AS UNSIGNED);
INSERT INTO t1 (id, grp, id_rev) VALUES (@id, @grp, @id_rev);
SET @rnd= RAND();
SET @id = CAST(@rnd * @rnd_max AS UNSIGNED);
SET @id_rev= @rnd_max - @id;
SET @grp= CAST(127.0 * @rnd AS UNSIGNED);
INSERT INTO t1 (id, grp, id_rev) VALUES (@id, @grp, @id_rev);
SET @rnd= RAND();
SET @id = CAST(@rnd * @rnd_max AS UNSIGNED);
SET @id_rev= @rnd_max - @id;
SET @grp= CAST(127.0 * @rnd AS UNSIGNED);
INSERT INTO t1 (id, grp, id_rev) VALUES (@id, @grp, @id_rev);
set @@read_buffer_size=2*1024*1024;
CREATE TABLE t2 SELECT * FROM t1;
INSERT INTO t1 (id, grp, id_rev) SELECT id, grp, id_rev FROM t2;
INSERT INTO t2 (id, grp, id_rev) SELECT id, grp, id_rev FROM t1;
INSERT INTO t1 (id, grp, id_rev) SELECT id, grp, id_rev FROM t2;
INSERT INTO t2 (id, grp, id_rev) SELECT id, grp, id_rev FROM t1;
INSERT INTO t1 (id, grp, id_rev) SELECT id, grp, id_rev FROM t2;
CREATE TABLE t3 (id INTEGER, grp TINYINT, id_rev INTEGER)
ENGINE= MRG_MYISAM UNION= (t1, t2);
SELECT COUNT(*) FROM t1;
COUNT(*)
130
SELECT COUNT(*) FROM t2;
COUNT(*)
80
SELECT COUNT(*) FROM t3;
COUNT(*)
210
SELECT COUNT(DISTINCT a1.id) FROM t3 AS a1, t3 AS a2
WHERE a1.id = a2.id GROUP BY a2.grp;
TRUNCATE TABLE t1;
SELECT COUNT(*) FROM t1;
COUNT(*)
0
SELECT COUNT(*) FROM t2;
COUNT(*)
80
SELECT COUNT(*) FROM t3;
COUNT(*)
80
DROP TABLE t1, t2, t3;
CREATE TABLE t1 (c1 INT) ENGINE=MyISAM;
CREATE TABLE t2 (c1 INT) ENGINE=MRG_MYISAM UNION=(t1) INSERT_METHOD=LAST;
INSERT INTO t2 VALUES (1);
SELECT * FROM t2;
c1
1
LOCK TABLES t2 WRITE, t1 WRITE;
FLUSH TABLES;
REPAIR TABLE t1;
Table Op Msg_type Msg_text
test.t1 repair status OK
CHECK TABLE t1;
Table Op Msg_type Msg_text
test.t1 check status OK
REPAIR TABLE t1;
Table Op Msg_type Msg_text
test.t1 repair status OK
UNLOCK TABLES;
CHECK TABLE t1 EXTENDED;
Table Op Msg_type Msg_text
test.t1 check status OK
LOCK TABLES t2 WRITE, t1 WRITE;
REPAIR TABLE t1;
Table Op Msg_type Msg_text
test.t1 repair status OK
CHECK TABLE t1;
Table Op Msg_type Msg_text
test.t1 check status OK
REPAIR TABLE t1;
Table Op Msg_type Msg_text
test.t1 repair status OK
UNLOCK TABLES;
CHECK TABLE t1 EXTENDED;
Table Op Msg_type Msg_text
test.t1 check status OK
DROP TABLE t1, t2;
CREATE TABLE t1 ( a INT ) ENGINE=MyISAM;
CREATE TABLE m1 ( a INT ) ENGINE=MRG_MYISAM UNION=(t1);
LOCK TABLES t1 WRITE, m1 WRITE;
FLUSH TABLE t1;
UNLOCK TABLES;
DROP TABLE m1, t1;
CREATE TABLE t1 ( a INT ) ENGINE=MyISAM;
CREATE TABLE m1 ( a INT ) ENGINE=MRG_MYISAM UNION=(t1);
LOCK TABLES m1 WRITE, t1 WRITE;
FLUSH TABLE t1;
UNLOCK TABLES;
DROP TABLE m1, t1;
CREATE TABLE t1 (c1 INT, c2 INT) ENGINE= MyISAM;
CREATE TABLE t2 (c1 INT, c2 INT) ENGINE= MyISAM;
CREATE TABLE t3 (c1 INT, c2 INT) ENGINE= MRG_MYISAM UNION(t1, t2);
INSERT INTO t1 VALUES (1, 1);
INSERT INTO t2 VALUES (2, 2);
SELECT * FROM t3;
c1 c2
1 1
2 2
ALTER TABLE t1 ENGINE= MEMORY;
INSERT INTO t1 VALUES (0, 0);
SELECT * FROM t3;
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
DROP TABLE t1, t2, t3;
CREATE TABLE t1 (c1 INT, KEY(c1));
CREATE TABLE t2 (c1 INT, KEY(c1)) ENGINE=MRG_MYISAM UNION=(t1)
INSERT_METHOD=FIRST;
LOCK TABLE t1 WRITE, t2 WRITE;
FLUSH TABLES t2, t1;
OPTIMIZE TABLE t1;
Table Op Msg_type Msg_text
test.t1 optimize status Table is already up to date
FLUSH TABLES t1;
UNLOCK TABLES;
FLUSH TABLES;
INSERT INTO t1 VALUES (1);
LOCK TABLE t1 WRITE, t2 WRITE;
FLUSH TABLES t2, t1;
OPTIMIZE TABLE t1;
Table Op Msg_type Msg_text
test.t1 optimize status OK
FLUSH TABLES t1;
UNLOCK TABLES;
DROP TABLE t1, t2;
CREATE TABLE t1 (ID INT) ENGINE=MYISAM;
CREATE TABLE m1 (ID INT) ENGINE=MRG_MYISAM UNION=(t1) INSERT_METHOD=FIRST;
INSERT INTO t1 VALUES ();
INSERT INTO m1 VALUES ();
LOCK TABLE t1 WRITE, m1 WRITE;
FLUSH TABLES m1, t1;
OPTIMIZE TABLE t1;
Table Op Msg_type Msg_text
test.t1 optimize status OK
FLUSH TABLES m1, t1;
UNLOCK TABLES;
DROP TABLE t1, m1;
2008-10-09 10:55:16 +02:00
CREATE TABLE tm1 (c1 INT) ENGINE=MRG_MYISAM UNION=(t1) INSERT_METHOD=FIRST;
SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE
TABLE_SCHEMA = 'test' and TABLE_NAME='tm1';
TABLE_CATALOG TABLE_SCHEMA TABLE_NAME TABLE_TYPE ENGINE VERSION ROW_FORMAT TABLE_ROWS AVG_ROW_LENGTH DATA_LENGTH MAX_DATA_LENGTH INDEX_LENGTH DATA_FREE AUTO_INCREMENT CREATE_TIME UPDATE_TIME CHECK_TIME TABLE_COLLATION CHECKSUM CREATE_OPTIONS TABLE_COMMENT
2010-02-20 11:07:32 +01:00
def test tm1 BASE TABLE NULL NULL NULL # # # # # # # # # # NULL # # Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
2008-10-09 10:55:16 +02:00
DROP TABLE tm1;
2008-04-25 23:45:58 +02:00
CREATE TABLE t1(C1 INT, C2 INT, KEY C1(C1), KEY C2(C2)) ENGINE=MYISAM;
CREATE TABLE t2(C1 INT, C2 INT, KEY C1(C1), KEY C2(C2)) ENGINE=MYISAM;
CREATE TABLE t3(C1 INT, C2 INT, KEY C1(C1), KEY C2(C2)) ENGINE=MYISAM;
CREATE TABLE t4(C1 INT, C2 INT, KEY C1(C1), KEY C2(C2))
ENGINE=MRG_MYISAM UNION=(t1, t2, t3);
INSERT INTO t1 VALUES (1,1), (1,2),(1,3), (1,4);
INSERT INTO t2 VALUES (2,1), (2,2),(2,3), (2,4);
INSERT INTO t3 VALUES (3,1), (3,2),(3,3), (3,4);
EXPLAIN SELECT COUNT(*) FROM t1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
EXPLAIN SELECT COUNT(*) FROM t4;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
DROP TABLE t1, t2, t3, t4;
2009-02-05 14:03:47 +01:00
CREATE TABLE t1(a INT, KEY(a));
INSERT INTO t1 VALUES(0),(1),(2),(3),(4);
ANALYZE TABLE t1;
Table Op Msg_type Msg_text
test.t1 analyze status OK
CREATE TABLE m1(a INT, KEY(a)) ENGINE=MERGE UNION=(t1);
SELECT CARDINALITY FROM INFORMATION_SCHEMA.STATISTICS WHERE TABLE_SCHEMA='test' AND TABLE_NAME='m1';
CARDINALITY
5
SELECT CARDINALITY FROM INFORMATION_SCHEMA.STATISTICS WHERE TABLE_SCHEMA='test' AND TABLE_NAME='m1';
CARDINALITY
5
SELECT CARDINALITY FROM INFORMATION_SCHEMA.STATISTICS WHERE TABLE_SCHEMA='test' AND TABLE_NAME='m1';
CARDINALITY
5
SELECT CARDINALITY FROM INFORMATION_SCHEMA.STATISTICS WHERE TABLE_SCHEMA='test' AND TABLE_NAME='m1';
CARDINALITY
5
DROP TABLE t1, m1;
2009-02-12 12:12:07 +01:00
#
# Bug #40675 MySQL 5.1 crash with index merge algorithm and Merge tables
#
# create MYISAM table t1 and insert values into it
CREATE TABLE t1(a INT);
INSERT INTO t1 VALUES(1);
# create MYISAM table t2 and insert values into it
CREATE TABLE t2(a INT, b INT, dummy CHAR(16) DEFAULT '', KEY(a), KEY(b));
INSERT INTO t2(a,b) VALUES
(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),(0,0),
(1,2);
# Create the merge table t3
CREATE TABLE t3(a INT, b INT, dummy CHAR(16) DEFAULT '', KEY(a), KEY(b))
ENGINE=MERGE UNION=(t2) INSERT_METHOD=FIRST;
# Lock tables t1 and t3 for write
LOCK TABLES t1 WRITE, t3 WRITE;
# Insert values into the merge table t3
INSERT INTO t3(a,b) VALUES(1,2);
# select from the join of t2 and t3 (The merge table)
SELECT t3.a FROM t1,t3 WHERE t3.b=2 AND t3.a=1;
a
1
1
# Unlock the tables
UNLOCK TABLES;
# drop the created tables
DROP TABLE t1, t2, t3;
2009-03-04 10:18:07 +01:00
# insert duplicate value in child table while merge table doesn't have key
create table t1 (
col1 int(10),
primary key (col1)
) ENGINE=MyISAM DEFAULT CHARSET=latin1;
CREATE TABLE m1 (
col1 int(10) NOT NULL
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 INSERT_METHOD=LAST UNION=(t1);
insert into m1 (col1) values (1);
insert into m1 (col1) values (1);
ERROR 23000: Duplicate entry '' for key '*UNKNOWN*'
drop table m1, t1;
2009-07-30 12:34:41 +02:00
#
# Bug#45800 crash when replacing into a merge table and there is a duplicate
#
# Replace duplicate value in child table when merge table doesn't have key
CREATE TABLE t1 (c1 INT PRIMARY KEY) ENGINE=MyISAM;
CREATE TABLE m1 (c1 INT NOT NULL) ENGINE=MRG_MyISAM INSERT_METHOD=LAST UNION=(t1);
INSERT INTO m1 VALUES (666);
SELECT * FROM m1;
c1
666
# insert the duplicate value into the merge table
REPLACE INTO m1 VALUES (666);
SELECT * FROM m1;
c1
666
DROP TABLE m1, t1;
# Insert... on duplicate key update (with duplicate values in the table)
CREATE TABLE t1 (c1 INT PRIMARY KEY) ENGINE=MyISAM;
CREATE TABLE m1 (c1 INT NOT NULL) ENGINE=MRG_MyISAM INSERT_METHOD=LAST UNION=(t1);
INSERT INTO m1 VALUES (666);
SELECT * FROM m1;
c1
666
# insert the duplicate value into the merge table
INSERT INTO m1 VALUES (666) ON DUPLICATE KEY UPDATE c1=c1+1;
SELECT * FROM m1;
c1
667
DROP TABLE m1, t1;
# Insert duplicate value on MERGE table, where, MERGE has a key but MyISAM has more keys
CREATE TABLE t1 (c1 INT, c2 INT, UNIQUE (c1), UNIQUE (c2));
CREATE TABLE m1 (c1 INT, c2 INT, UNIQUE (c1)) ENGINE=MRG_MyISAM INSERT_METHOD=LAST UNION=(t1);
INSERT INTO m1 VALUES (1,2);
# insert the duplicate value into the merge table
INSERT INTO m1 VALUES (3,2);
ERROR 23000: Duplicate entry '' for key '*UNKNOWN*'
DROP TABLE m1,t1;
# Try to define MERGE and MyISAM with keys on different columns
CREATE TABLE t1 (c1 INT, c2 INT, UNIQUE (c1));
CREATE TABLE m1 (c1 INT, c2 INT, UNIQUE (c2)) ENGINE=MRG_MyISAM INSERT_METHOD=LAST UNION=(t1);
# Try accessing the merge table for inserts (error occurs)
INSERT INTO m1 VALUES (1,2);
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
INSERT INTO m1 VALUES (1,4);
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
DROP TABLE m1,t1;
2009-04-17 07:51:51 +02:00
CREATE TABLE t1 (
col1 INT(10)
) ENGINE=MyISAM DEFAULT CHARSET=latin1;
CREATE VIEW v1 as SELECT * FROM t1;
CREATE TABLE m1 (
col1 INT(10)
)ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 INSERT_METHOD=LAST UNION=(v1);
#Select should detect that the child table is a view and fail.
SELECT * FROM m1;
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
DROP VIEW v1;
DROP TABLE m1, t1;
2009-07-10 13:34:03 +02:00
#
# Bug #45796: invalid memory reads and writes when altering merge and
# base tables
#
CREATE TABLE t1(c1 INT) ENGINE=MyISAM;
CREATE TABLE m1(c1 INT) ENGINE=MERGE UNION=(t1);
ALTER TABLE m1 ADD INDEX idx_c1(c1);
SELECT * FROM m1;
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
ALTER TABLE t1 ADD INDEX idx_c1(c1);
SELECT * FROM m1;
c1
DROP TABLE m1;
DROP TABLE t1;
2009-07-16 01:23:57 +02:00
#
# Bug45781 infinite hang/crash in "opening tables" after handler tries to
# open merge table
#
DROP TABLE IF EXISTS m1,t1;
CREATE TABLE t1(a int)engine=myisam;
CREATE TABLE t2(a int)engine=myisam;
CREATE TABLE t3(a int)engine=myisam;
CREATE TABLE t4(a int)engine=myisam;
CREATE TABLE t5(a int)engine=myisam;
CREATE TABLE t6(a int)engine=myisam;
CREATE TABLE t7(a int)engine=myisam;
CREATE TABLE m1(a int)engine=merge union=(t1,t2,t3,t4,t5,t6,t7);
SELECT 1 FROM m1;
1
HANDLER m1 OPEN;
ERROR HY000: Table storage engine for 'm1' doesn't have this option
DROP TABLE m1,t1,t2,t3,t4,t5,t6,t7;
SELECT 1 FROM m1;
ERROR 42S02: Table 'test.m1' doesn't exist
2009-08-13 21:49:28 +02:00
#
# Bug #46614: Assertion in show_create_trigger()
#
CREATE TABLE t1(a int);
CREATE TABLE t2(a int);
CREATE TABLE t3(a int) ENGINE = MERGE UNION(t1, t2);
CREATE TRIGGER tr1 AFTER INSERT ON t3 FOR EACH ROW CALL foo();
SHOW CREATE TRIGGER tr1;
Trigger sql_mode SQL Original Statement character_set_client collation_connection Database Collation
tr1 CREATE DEFINER=`root`@`localhost` TRIGGER tr1 AFTER INSERT ON t3 FOR EACH ROW CALL foo() latin1 latin1_swedish_ci latin1_swedish_ci
DROP TRIGGER tr1;
DROP TABLE t1, t2, t3;
2010-03-03 11:49:03 +01:00
#
# BUG#48265 - MRG_MYISAM problem (works in 5.0.85, does't work in 5.1.40)
#
CREATE DATABASE `test/1`;
CREATE TABLE `test/1`.`t/1`(a INT);
CREATE TABLE m1(a INT) ENGINE=MERGE UNION=(`test/1`.`t/1`);
SELECT * FROM m1;
a
SHOW CREATE TABLE m1;
Table Create Table
m1 CREATE TABLE `m1` (
`a` int(11) DEFAULT NULL
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`test/1`.`t/1`)
DROP TABLE m1;
CREATE TABLE `test/1`.m1(a INT) ENGINE=MERGE UNION=(`test/1`.`t/1`);
SELECT * FROM `test/1`.m1;
a
SHOW CREATE TABLE `test/1`.m1;
Table Create Table
m1 CREATE TABLE `m1` (
`a` int(11) DEFAULT NULL
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`t/1`)
DROP TABLE `test/1`.m1;
DROP TABLE `test/1`.`t/1`;
CREATE TEMPORARY TABLE `test/1`.`t/1`(a INT);
CREATE TEMPORARY TABLE m1(a INT) ENGINE=MERGE UNION=(`test/1`.`t/1`);
SELECT * FROM m1;
a
SHOW CREATE TABLE m1;
Table Create Table
m1 CREATE TEMPORARY TABLE `m1` (
`a` int(11) DEFAULT NULL
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`test/1`.`t/1`)
DROP TABLE m1;
CREATE TEMPORARY TABLE `test/1`.m1(a INT) ENGINE=MERGE UNION=(`test/1`.`t/1`);
SELECT * FROM `test/1`.m1;
a
SHOW CREATE TABLE `test/1`.m1;
Table Create Table
m1 CREATE TEMPORARY TABLE `m1` (
`a` int(11) DEFAULT NULL
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`t/1`)
DROP TABLE `test/1`.m1;
DROP TABLE `test/1`.`t/1`;
DROP DATABASE `test/1`;
CREATE TABLE `t@1`(a INT);
SELECT * FROM m1;
a
SHOW CREATE TABLE m1;
Table Create Table
m1 CREATE TABLE `m1` (
`a` int(11) DEFAULT NULL
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`t@1`)
DROP TABLE `t@1`;
CREATE DATABASE `test@1`;
CREATE TABLE `test@1`.`t@1`(a INT);
FLUSH TABLE m1;
SELECT * FROM m1;
a
SHOW CREATE TABLE m1;
Table Create Table
m1 CREATE TABLE `m1` (
`a` int(11) DEFAULT NULL
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`test@1`.`t@1`)
DROP TABLE m1;
DROP TABLE `test@1`.`t@1`;
DROP DATABASE `test@1`;
2010-03-19 07:01:02 +01:00
#
# Bug#51494c rash with join, explain and 'sounds like' operator
#
CREATE TABLE t1 (a INT) ENGINE=MYISAM;
INSERT INTO t1 VALUES(1);
CREATE TABLE t2 (b INT NOT NULL,c INT,d INT,e BLOB NOT NULL,
KEY idx0 (d, c)) ENGINE=MERGE;
EXPLAIN SELECT * FROM t1 NATURAL RIGHT JOIN
t2 WHERE b SOUNDS LIKE e AND d = 1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables
DROP TABLE t2, t1;
2008-04-25 23:45:58 +02:00
End of 5.1 tests
2009-10-13 21:04:58 +02:00
#
# An additional test case for Bug#27430 Crash in subquery code
# when in PS and table DDL changed after PREPARE
#
# Test merge table with too many merge children.
#
drop table if exists t_parent;
set @save_table_definition_cache=@@global.table_definition_cache;
#
# Set @@global.table_definition_cache to minimum
#
set @@global.table_definition_cache=400;
set @a=null;
#
# Create 400 merge children
#
set @a=concat("create table t_parent (a int) union(", @a,
") insert_method=first engine=mrg_myisam");
prepare stmt from @a;
execute stmt;
prepare stmt from "select * from t_parent";
execute stmt;
ERROR HY000: Prepared statement needs to be re-prepared
execute stmt;
ERROR HY000: Prepared statement needs to be re-prepared
execute stmt;
ERROR HY000: Prepared statement needs to be re-prepared
deallocate prepare stmt;
#
# Create merge parent
#
#
# Cleanup
#
drop table t_parent;
set @@global.table_definition_cache=@save_table_definition_cache;
2009-12-03 00:09:22 +01:00
DROP DATABASE IF EXISTS mysql_test1;
CREATE DATABASE mysql_test1;
CREATE TABLE t1 ... DATA DIRECTORY=... INDEX DIRECTORY=...
CREATE TABLE mysql_test1.t2 ... DATA DIRECTORY=... INDEX DIRECTORY=...
CREATE TABLE m1 (c1 INT) ENGINE=MRG_MYISAM UNION=(t1,mysql_test1.t2)
INSERT_METHOD=LAST;
INSERT INTO t1 VALUES (1);
INSERT INTO mysql_test1.t2 VALUES (2);
SELECT * FROM m1;
c1
1
2
DROP TABLE t1, mysql_test1.t2, m1;
DROP DATABASE mysql_test1;
CREATE TABLE t1 (c1 INT);
CREATE TABLE t2 (c1 INT);
INSERT INTO t1 (c1) VALUES (1);
CREATE TABLE tm1 (c1 INT) ENGINE=MRG_MYISAM UNION=(t1,t2) INSERT_METHOD=FIRST;
CREATE TABLE t3 (c1 INT);
INSERT INTO t3 (c1) VALUES (1);
CREATE FUNCTION f1() RETURNS INT RETURN (SELECT MAX(c1) FROM t3);
CREATE VIEW v1 AS SELECT foo.c1 c1, f1() c2, bar.c1 c3, f1() c4
FROM tm1 foo, tm1 bar, t3;
SELECT * FROM v1;
c1 c2 c3 c4
1 1 1 1
DROP FUNCTION f1;
DROP VIEW v1;
DROP TABLE tm1, t1, t2, t3;
CREATE TEMPORARY TABLE t1 (c1 INT);
CREATE TEMPORARY TABLE t2 (c1 INT);
CREATE TEMPORARY TABLE tm1 (c1 INT) ENGINE=MRG_MYISAM UNION=(t1,t2)
INSERT_METHOD=FIRST;
CREATE FUNCTION f1() RETURNS INT RETURN (SELECT MAX(c1) FROM tm1);
INSERT INTO tm1 (c1) VALUES (1);
SELECT f1() FROM (SELECT 1) AS c1;
f1()
1
DROP FUNCTION f1;
DROP TABLE tm1, t1, t2;
CREATE FUNCTION f1() RETURNS INT
BEGIN
CREATE TEMPORARY TABLE t1 (c1 INT);
CREATE TEMPORARY TABLE t2 (c1 INT);
CREATE TEMPORARY TABLE tm1 (c1 INT) ENGINE=MRG_MYISAM UNION=(t1,t2);
INSERT INTO t1 (c1) VALUES (1);
RETURN (SELECT MAX(c1) FROM tm1);
END|
SELECT f1() FROM (SELECT 1 UNION SELECT 1) c1;
f1()
1
DROP FUNCTION f1;
DROP TABLE tm1, t1, t2;
CREATE TEMPORARY TABLE t1 (c1 INT);
INSERT INTO t1 (c1) VALUES (1);
CREATE TEMPORARY TABLE tm1 (c1 INT) ENGINE=MRG_MYISAM UNION=(t1);
CREATE FUNCTION f1() RETURNS INT
BEGIN
CREATE TEMPORARY TABLE t2 (c1 INT);
ALTER TEMPORARY TABLE tm1 UNION=(t1,t2);
INSERT INTO t2 (c1) VALUES (2);
RETURN (SELECT MAX(c1) FROM tm1);
END|
ERROR 0A000: ALTER VIEW is not allowed in stored procedures
DROP TABLE tm1, t1;
CREATE TABLE t1 (c1 INT) ENGINE=MyISAM;
CREATE TABLE tm1 (c1 INT) ENGINE=MRG_MYISAM UNION=(t1) INSERT_METHOD=LAST;
INSERT INTO tm1 VALUES (1);
SELECT * FROM tm1;
c1
1
DROP TABLE tm1, t1;
CREATE FUNCTION f1() RETURNS INT
BEGIN
INSERT INTO tm1 VALUES (1);
RETURN (SELECT MAX(c1) FROM tm1);
END|
CREATE TABLE t1 (c1 INT) ENGINE=MyISAM;
CREATE TABLE tm1 (c1 INT) ENGINE=MRG_MYISAM UNION=(t1) INSERT_METHOD=LAST;
SELECT f1();
f1()
1
DROP FUNCTION f1;
DROP TABLE tm1, t1;
CREATE TABLE t1 (c1 INT) ENGINE=MyISAM;
CREATE TABLE tm1 (c1 INT) ENGINE=MRG_MYISAM UNION=(t1) INSERT_METHOD=LAST;
LOCK TABLE tm1 WRITE;
INSERT INTO tm1 VALUES (1);
SELECT * FROM tm1;
c1
1
UNLOCK TABLES;
DROP TABLE tm1, t1;
CREATE FUNCTION f1() RETURNS INT
BEGIN
INSERT INTO tm1 VALUES (1);
RETURN (SELECT MAX(c1) FROM tm1);
END|
CREATE TABLE t1 (c1 INT) ENGINE=MyISAM;
CREATE TABLE tm1 (c1 INT) ENGINE=MRG_MYISAM UNION=(t1) INSERT_METHOD=LAST;
LOCK TABLE tm1 WRITE;
SELECT f1();
f1()
1
UNLOCK TABLES;
DROP FUNCTION f1;
DROP TABLE tm1, t1;
CREATE TABLE t1 (c1 INT) ENGINE=MyISAM;
CREATE TABLE t2 (c1 INT) ENGINE=MyISAM;
CREATE TABLE tm1 (c1 INT) ENGINE=MRG_MYISAM UNION=(t1) INSERT_METHOD=LAST;
CREATE TRIGGER t2_ai AFTER INSERT ON t2
FOR EACH ROW INSERT INTO tm1 VALUES(11);
LOCK TABLE t2 WRITE;
INSERT INTO t2 VALUES (2);
SELECT * FROM tm1;
c1
11
SELECT * FROM t2;
c1
2
UNLOCK TABLES;
DROP TRIGGER t2_ai;
DROP TABLE tm1, t1, t2;
CREATE TEMPORARY TABLE t1 (c1 INT) ENGINE=MyISAM;
CREATE TEMPORARY TABLE tm1 (c1 INT) ENGINE=MRG_MYISAM UNION=(t1)
INSERT_METHOD=LAST;
INSERT INTO tm1 VALUES (1);
SELECT * FROM tm1;
c1
1
DROP TABLE tm1, t1;
CREATE FUNCTION f1() RETURNS INT
BEGIN
INSERT INTO tm1 VALUES (1);
RETURN (SELECT MAX(c1) FROM tm1);
END|
CREATE TEMPORARY TABLE t1 (c1 INT) ENGINE=MyISAM;
CREATE TEMPORARY TABLE tm1 (c1 INT) ENGINE=MRG_MYISAM UNION=(t1)
INSERT_METHOD=LAST;
SELECT f1();
f1()
1
DROP FUNCTION f1;
DROP TABLE tm1, t1;
CREATE TEMPORARY TABLE t1 (c1 INT) ENGINE=MyISAM;
CREATE TEMPORARY TABLE tm1 (c1 INT) ENGINE=MRG_MYISAM UNION=(t1)
INSERT_METHOD=LAST;
CREATE TABLE t9 (c1 INT) ENGINE=MyISAM;
LOCK TABLE t9 WRITE;
INSERT INTO tm1 VALUES (1);
SELECT * FROM tm1;
c1
1
UNLOCK TABLES;
DROP TABLE tm1, t1, t9;
CREATE FUNCTION f1() RETURNS INT
BEGIN
INSERT INTO tm1 VALUES (1);
RETURN (SELECT MAX(c1) FROM tm1);
END|
CREATE TEMPORARY TABLE t1 (c1 INT) ENGINE=MyISAM;
CREATE TEMPORARY TABLE tm1 (c1 INT) ENGINE=MRG_MYISAM UNION=(t1)
INSERT_METHOD=LAST;
CREATE TABLE t9 (c1 INT) ENGINE=MyISAM;
LOCK TABLE t9 WRITE;
SELECT f1();
f1()
1
UNLOCK TABLES;
DROP FUNCTION f1;
DROP TABLE tm1, t1, t9;
CREATE TEMPORARY TABLE t1 (c1 INT) ENGINE=MyISAM;
CREATE TEMPORARY TABLE tm1 (c1 INT) ENGINE=MRG_MYISAM UNION=(t1)
INSERT_METHOD=LAST;
CREATE TABLE t2 (c1 INT) ENGINE=MyISAM;
CREATE TRIGGER t2_ai AFTER INSERT ON t2
FOR EACH ROW INSERT INTO tm1 VALUES(11);
LOCK TABLE t2 WRITE;
INSERT INTO t2 VALUES (2);
SELECT * FROM tm1;
c1
11
SELECT * FROM t2;
c1
2
UNLOCK TABLES;
DROP TRIGGER t2_ai;
DROP TABLE tm1, t1, t2;
#
2010-02-15 17:35:53 +01:00
# Don't allow an update of a MERGE child in a trigger
# if the table's already being modified by the main
# statement.
2009-12-03 00:09:22 +01:00
#
CREATE TABLE t1 (c1 INT) ENGINE=MyISAM;
CREATE TABLE tm1 (c1 INT) ENGINE=MRG_MYISAM UNION=(t1)
INSERT_METHOD=LAST;
CREATE TRIGGER tm1_ai AFTER INSERT ON tm1
FOR EACH ROW INSERT INTO t1 VALUES(11);
LOCK TABLE tm1 WRITE, t1 WRITE;
INSERT INTO tm1 VALUES (1);
2010-02-15 17:35:53 +01:00
ERROR HY000: Can't update table 't1' in stored function/trigger because it is already used by statement which invoked this stored function/trigger.
SELECT * FROM tm1;
c1
1
UNLOCK TABLES;
LOCK TABLE t1 WRITE, tm1 WRITE;
INSERT INTO tm1 VALUES (1);
ERROR HY000: Can't update table 't1' in stored function/trigger because it is already used by statement which invoked this stored function/trigger.
SELECT * FROM tm1;
c1
1
1
UNLOCK TABLES;
DROP TRIGGER tm1_ai;
DROP TABLE tm1, t1;
#
# Don't select MERGE child when trying to get a prelocked table.
#
# Due to a limitation demonstrated by the previous test
# we can no longer use a write-locked prelocked table.
# The test is kept for historical purposes.
#
CREATE TABLE t1 (c1 INT) ENGINE=MyISAM;
CREATE TABLE tm1 (c1 INT) ENGINE=MRG_MYISAM UNION=(t1)
INSERT_METHOD=LAST;
CREATE TRIGGER tm1_ai AFTER INSERT ON tm1
FOR EACH ROW SELECT max(c1) FROM t1 INTO @var;
LOCK TABLE tm1 WRITE, t1 WRITE;
INSERT INTO tm1 VALUES (1);
2009-12-03 00:09:22 +01:00
SELECT * FROM tm1;
c1
1
UNLOCK TABLES;
LOCK TABLE t1 WRITE, tm1 WRITE;
INSERT INTO tm1 VALUES (1);
SELECT * FROM tm1;
c1
1
1
UNLOCK TABLES;
DROP TRIGGER tm1_ai;
DROP TABLE tm1, t1;
CREATE TABLE t1 (c1 INT) ENGINE=MyISAM;
CREATE TABLE t2 (c1 INT) ENGINE=MyISAM;
CREATE TABLE t3 (c1 INT) ENGINE=MyISAM;
CREATE TABLE t4 (c1 INT) ENGINE=MyISAM;
CREATE TABLE t5 (c1 INT) ENGINE=MyISAM;
CREATE TABLE tm1 (c1 INT) ENGINE=MRG_MYISAM UNION=(t1,t2,t3,t4,t5)
INSERT_METHOD=LAST;
CREATE TRIGGER t2_au AFTER UPDATE ON t2
2010-02-15 17:35:53 +01:00
FOR EACH ROW SELECT MAX(c1) FROM t1 INTO @var;
2009-12-03 00:09:22 +01:00
CREATE FUNCTION f1() RETURNS INT
RETURN (SELECT MAX(c1) FROM t4);
LOCK TABLE tm1 WRITE, t1 WRITE, t2 WRITE, t3 WRITE, t4 WRITE, t5 WRITE;
INSERT INTO t1 VALUES(1);
INSERT INTO t2 VALUES(2);
INSERT INTO t3 VALUES(3);
INSERT INTO t4 VALUES(4);
INSERT INTO t5 VALUES(5);
UPDATE t2, tm1 SET t2.c1=f1();
FLUSH TABLES;
FLUSH TABLES;
UNLOCK TABLES;
SELECT * FROM tm1;
c1
1
4
3
4
5
DROP TRIGGER t2_au;
DROP FUNCTION f1;
DROP TABLE tm1, t1, t2, t3, t4, t5;
2009-12-09 14:41:56 +01:00
#
2010-06-25 17:32:59 +02:00
# Bug#47633 - assert in ha_myisammrg::info during OPTIMIZE
#
CREATE TEMPORARY TABLE t1 (c1 INT);
ALTER TABLE t1 ENGINE=MERGE UNION(t_not_exists,t1);
OPTIMIZE TABLE t1;
Table Op Msg_type Msg_text
test.t1 optimize Error Table 'test.t_not_exists' doesn't exist
test.t1 optimize Error Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
test.t1 optimize note The storage engine for the table doesn't support optimize
DROP TABLE t1;
#
2009-12-09 14:41:56 +01:00
# Bug47098 assert in MDL_context::destroy on HANDLER
# <damaged merge table> OPEN
#
# Test that merge tables are closed correctly when opened using
# HANDLER ... OPEN.
# The general case.
DROP TABLE IF EXISTS t1, t2, t3;
# Connection con1.
CREATE TABLE t1 (c1 int);
CREATE TABLE t2 (c1 int);
CREATE TABLE t3 (c1 int) ENGINE = MERGE UNION (t1,t2);
START TRANSACTION;
HANDLER t3 OPEN;
ERROR HY000: Table storage engine for 't3' doesn't have this option
DROP TABLE t1, t2, t3;
# Connection default.
# Disconnecting con1, all mdl_tickets must have been released.
# The bug-specific case.
# Connection con1.
CREATE TABLE t1 (c1 int);
CREATE TABLE t2 (c1 int);
CREATE TABLE t3 (c1 int) ENGINE = MERGE UNION (t1,t2);
DROP TABLE t2;
START TRANSACTION;
HANDLER t3 OPEN;
ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
DROP TABLE t1, t3;
# Connection default.
# Disconnecting con1, all mdl_tickets must have been released.
2010-02-15 17:35:53 +01:00
#
# A test case for Bug#47648 main.merge fails sporadically
#
# Make sure we correctly maintain lex->query_tables_last_own.
#
create table t1 (c1 int not null);
create table t2 (c1 int not null);
create table t3 (c1 int not null);
create function f1 () returns int return (select max(c1) from t3);
create table t4 (c1 int not null) engine=merge union=(t1,t2) insert_method=last ;
select * from t4 where c1 < f1();
c1
prepare stmt from "select * from t4 where c1 < f1()";
execute stmt;
c1
execute stmt;
c1
execute stmt;
c1
drop function f1;
execute stmt;
ERROR 42000: FUNCTION test.f1 does not exist
execute stmt;
ERROR 42000: FUNCTION test.f1 does not exist
drop table t4, t3, t2, t1;
2010-02-26 13:40:25 +01:00
#
# Bug#51240 ALTER TABLE of a locked MERGE table fails
#
DROP TABLE IF EXISTS m1, t1;
CREATE TABLE t1 (c1 INT);
CREATE TABLE m1 (c1 INT) ENGINE=MRG_MyISAM UNION=(t1);
LOCK TABLE m1 WRITE;
ALTER TABLE m1 ADD INDEX (c1);
UNLOCK TABLES;
DROP TABLE m1, t1;
2010-06-11 10:14:38 +02:00
#
2010-06-25 17:32:59 +02:00
# If children are to be altered, they need an explicit lock.
#
CREATE TABLE t1 (c1 INT);
CREATE TABLE m1 (c1 INT) ENGINE=MRG_MyISAM UNION=(t1);
LOCK TABLE m1 WRITE;
ALTER TABLE t1 ADD INDEX (c1);
ERROR HY000: Table 't1' was locked with a READ lock and can't be updated
LOCK TABLE m1 WRITE, t1 WRITE;
ALTER TABLE t1 ADD INDEX (c1);
UNLOCK TABLES;
DROP TABLE m1, t1;
#
2010-06-11 10:14:38 +02:00
# Test for bug #37371 "CREATE TABLE LIKE merge loses UNION parameter"
#
drop tables if exists t1, m1, m2;
create table t1 (i int) engine=myisam;
create table m1 (i int) engine=mrg_myisam union=(t1) insert_method=first;
create table m2 like m1;
# Table definitions should match
show create table m1;
Table Create Table
m1 CREATE TABLE `m1` (
`i` int(11) DEFAULT NULL
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 INSERT_METHOD=FIRST UNION=(`t1`)
show create table m2;
Table Create Table
m2 CREATE TABLE `m2` (
`i` int(11) DEFAULT NULL
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 INSERT_METHOD=FIRST UNION=(`t1`)
drop tables m1, m2, t1;
2009-12-03 00:09:22 +01:00
End of 6.0 tests