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mariadb/mysql-test/r/merge.result
unknown f631b361b6 Table definition cache, part 2 
The table opening process now works the following way:
- Create common TABLE_SHARE object
- Read the .frm file and unpack it into the TABLE_SHARE object
- Create a TABLE object based on the information in the TABLE_SHARE
  object and open a handler to the table object

Other noteworthy changes:
- In TABLE_SHARE the most common strings are now LEX_STRING's
- Better error message when table is not found
- Variable table_cache is now renamed 'table_open_cache'
- New variable 'table_definition_cache' that is the number of table defintions that will be cached
- strxnmov() calls are now fixed to avoid overflows
- strxnmov() will now always add one end \0 to result
- engine objects are now created with a TABLE_SHARE object instead of a TABLE object.
- After creating a field object one must call field->init(table) before using it

- For a busy system this change will give you:
 - Less memory usage for table object
 - Faster opening of tables (if it's has been in use or is in table definition cache)
 - Allow you to cache many table definitions objects
 - Faster drop of table


mysql-test/mysql-test-run.sh:
  Fixed some problems with --gdb option
  Test both with socket and tcp/ip port that all old servers are killed
mysql-test/r/flush_table.result:
  More tests with lock table with 2 threads + flush table
mysql-test/r/information_schema.result:
  Removed old (now wrong) result
mysql-test/r/innodb.result:
  Better error messages (thanks to TDC patch)
mysql-test/r/merge.result:
  Extra flush table test
mysql-test/r/ndb_bitfield.result:
  Better error messages (thanks to TDC patch)
mysql-test/r/ndb_partition_error.result:
  Better error messages (thanks to TDC patch)
mysql-test/r/query_cache.result:
  Remove tables left from old tests
mysql-test/r/temp_table.result:
  Test truncate with temporary tables
mysql-test/r/variables.result:
  Table_cache -> Table_open_cache
mysql-test/t/flush_table.test:
  More tests with lock table with 2 threads + flush table
mysql-test/t/merge.test:
  Extra flush table test
mysql-test/t/multi_update.test:
  Added 'sleep' to make test predictable
mysql-test/t/query_cache.test:
  Remove tables left from old tests
mysql-test/t/temp_table.test:
  Test truncate with temporary tables
mysql-test/t/variables.test:
  Table_cache -> Table_open_cache
mysql-test/valgrind.supp:
  Remove warning that may happens becasue threads dies in different order
mysys/hash.c:
  Fixed wrong DBUG_PRINT
mysys/mf_dirname.c:
  More DBUG
mysys/mf_pack.c:
  Better comment
mysys/mf_tempdir.c:
  More DBUG
  Ensure that we call cleanup_dirname() on all temporary directory paths.
  
  If we don't do this, we will get a failure when comparing temporary table
  names as in some cases the temporary table name is run through convert_dirname())
mysys/my_alloc.c:
  Indentation fix
sql/examples/ha_example.cc:
  We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/examples/ha_example.h:
  We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/examples/ha_tina.cc:
  We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/examples/ha_tina.h:
  We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/field.cc:
  Update for table definition cache:
  - Field creation now takes TABLE_SHARE instead of TABLE as argument
    (This is becasue field definitions are now cached in TABLE_SHARE)
    When a field is created, one now must call field->init(TABLE) before using it
  - Use s->db instead of s->table_cache_key
  - Added Field::clone() to create a field in TABLE from a field in TABLE_SHARE
  - make_field() takes TABLE_SHARE as argument instead of TABLE
  - move_field() -> move_field_offset()
sql/field.h:
  Update for table definition cache:
  - Field creation now takes TABLE_SHARE instead of TABLE as argument
    (This is becasue field definitions are now cached in TABLE_SHARE)
    When a field is created, one now must call field->init(TABLE) before using it
  - Added Field::clone() to create a field in TABLE from a field in TABLE_SHARE
  - make_field() takes TABLE_SHARE as argument instead of TABLE
  - move_field() -> move_field_offset()
sql/ha_archive.cc:
  We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/ha_archive.h:
  We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/ha_berkeley.cc:
  We new use TABLE_SHARE instead of TABLE when creating engine handlers
  Changed name of argument create() to not hide internal 'table' variable.
  table->s  -> table_share
sql/ha_berkeley.h:
  We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/ha_blackhole.cc:
  We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/ha_blackhole.h:
  We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/ha_federated.cc:
  We new use TABLE_SHARE instead of TABLE when creating engine handlers
  Fixed comments
  Remove index variable and replace with pointers (simple optimization)
  move_field() -> move_field_offset()
  Removed some strlen() calls
sql/ha_federated.h:
  We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/ha_heap.cc:
  We new use TABLE_SHARE instead of TABLE when creating engine handlers
  Simplify delete_table() and create() as the given file names are now without extension
sql/ha_heap.h:
  We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/ha_innodb.cc:
  We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/ha_innodb.h:
  We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/ha_myisam.cc:
  We new use TABLE_SHARE instead of TABLE when creating engine handlers
  Remove not needed fn_format()
  Fixed for new table->s structure
sql/ha_myisam.h:
  We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/ha_myisammrg.cc:
  We new use TABLE_SHARE instead of TABLE when creating engine handlers
  Don't set 'is_view' for MERGE tables
  Use new interface to find_temporary_table()
sql/ha_myisammrg.h:
  We new use TABLE_SHARE instead of TABLE when creating engine handlers
  Added flag HA_NO_COPY_ON_ALTER
sql/ha_ndbcluster.cc:
  We new use TABLE_SHARE instead of TABLE when creating engine handlers
  Fixed wrong calls to strxnmov()
  Give error HA_ERR_TABLE_DEF_CHANGED if table definition has changed
  drop_table -> intern_drop_table()
  table->s -> table_share
  Move part_info to TABLE
  Fixed comments & DBUG print's
  New arguments to print_error()
sql/ha_ndbcluster.h:
  We new use TABLE_SHARE instead of TABLE when creating engine handlers
sql/ha_partition.cc:
  We new use TABLE_SHARE instead of TABLE when creating engine handlers
  We can't set up or use part_info when creating handler as there is not yet any table object
  New ha_intialise() to work with TDC (Done by Mikael)
sql/ha_partition.h:
  We new use TABLE_SHARE instead of TABLE when creating engine handlers
  Got set_part_info() from Mikael
sql/handler.cc:
  We new use TABLE_SHARE instead of TABLE when creating engine handlers
  ha_delete_table() now also takes database as an argument
  handler::ha_open() now takes TABLE as argument
  ha_open() now calls ha_allocate_read_write_set()
  Simplify ha_allocate_read_write_set()
  Remove ha_deallocate_read_write_set()
  Use table_share (Cached by table definition cache)
sql/handler.h:
  New table flag: HA_NO_COPY_ON_ALTER (used by merge tables)
  Remove ha_deallocate_read_write_set()
  get_new_handler() now takes TABLE_SHARE as argument
  ha_delete_table() now gets database as argument
sql/item.cc:
  table_name and db are now LEX_STRING objects
  When creating fields, we have now have to call field->init(table)
  move_field -> move_field_offset()
sql/item.h:
  tmp_table_field_from_field_type() now takes an extra paramenter 'fixed_length' to allow one to force usage of CHAR
   instead of BLOB
sql/item_cmpfunc.cc:
  Fixed call to tmp_table_field_from_field_type()
sql/item_create.cc:
  Assert if new not handled cast type
sql/item_func.cc:
  When creating fields, we have now have to call field->init(table)
  dummy_table used by 'sp' now needs a TABLE_SHARE object
sql/item_subselect.cc:
  Trivial code cleanups
sql/item_sum.cc:
  When creating fields, we have now have to call field->init(table)
sql/item_timefunc.cc:
  Item_func_str_to_date::tmp_table_field() now replaced by call to
   tmp_table_field_from_field_type() (see item_timefunc.h)
sql/item_timefunc.h:
  Simply tmp_table_field()
sql/item_uniq.cc:
  When creating fields, we have now have to call field->init(table)
sql/key.cc:
  Added 'KEY' argument to 'find_ref_key' to simplify code
sql/lock.cc:
  More debugging
  Use create_table_def_key() to create key for table cache
  Allocate TABLE_SHARE properly when creating name lock
  Fix that locked_table_name doesn't test same table twice
sql/mysql_priv.h:
  New functions for table definition cache
  New interfaces to a lot of functions.
  New faster interface to find_temporary_table() and close_temporary_table()
sql/mysqld.cc:
  Added support for table definition cache of size 'table_def_size'
  Fixed som calls to strnmov()
  Changed name of 'table_cache' to 'table_open_cache'
sql/opt_range.cc:
  Use new interfaces
  Fixed warnings from valgrind
sql/parse_file.cc:
  Safer calls to strxnmov()
  Fixed typo
sql/set_var.cc:
  Added variable 'table_definition_cache'
  Variable table_cache renamed to 'table_open_cache'
sql/slave.cc:
  Use new interface
sql/sp.cc:
  Proper use of TABLE_SHARE
sql/sp_head.cc:
  Remove compiler warnings
  We have now to call field->init(table)
sql/sp_head.h:
  Pointers to parsed strings are now const
sql/sql_acl.cc:
  table_name is now a LEX_STRING
sql/sql_base.cc:
  Main implementation of table definition cache
  (The #ifdef's are there for the future when table definition cache will replace open table cache)
  Now table definitions are cached indepndent of open tables, which will speed up things when a table is in use at once from several places
  Views are not yet cached; For the moment we only cache if a table is a view or not.
  
  Faster implementation of find_temorary_table()
  Replace 'wait_for_refresh()' with the more general function 'wait_for_condition()'
  Drop table is slightly faster as we can use the table definition cache to know the type of the table
sql/sql_cache.cc:
  table_cache_key and table_name are now LEX_STRING
  'sDBUG print fixes
sql/sql_class.cc:
  table_cache_key is now a LEX_STRING
  safer strxnmov()
sql/sql_class.h:
  Added number of open table shares (table definitions)
sql/sql_db.cc:
  safer strxnmov()
sql/sql_delete.cc:
  Use new interface to find_temporary_table()
sql/sql_derived.cc:
  table_name is now a LEX_STRING
sql/sql_handler.cc:
  TABLE_SHARE->db and TABLE_SHARE->table_name are now LEX_STRING's
sql/sql_insert.cc:
  TABLE_SHARE->db and TABLE_SHARE->table_name are now LEX_STRING's
sql/sql_lex.cc:
  Make parsed string a const (to quickly find out if anything is trying to change the query string)
sql/sql_lex.h:
  Make parsed string a const (to quickly find out if anything is trying to change the query string)
sql/sql_load.cc:
  Safer strxnmov()
sql/sql_parse.cc:
  Better error if wrong DB name
sql/sql_partition.cc:
  part_info moved to TABLE from TABLE_SHARE
  Indentation changes
sql/sql_select.cc:
  Indentation fixes
  Call field->init(TABLE) for new created fields
  Update create_tmp_table() to use TABLE_SHARE properly
sql/sql_select.h:
  Call field->init(TABLE) for new created fields
sql/sql_show.cc:
  table_name is now a LEX_STRING
  part_info moved to TABLE
sql/sql_table.cc:
  Use table definition cache to speed up delete of tables
  Fixed calls to functions with new interfaces
  Don't use 'share_not_to_be_used'
  Instead of doing openfrm() when doing repair, we now have to call
  get_table_share() followed by open_table_from_share().
  Replace some fn_format() with faster unpack_filename().
  Safer strxnmov()
  part_info is now in TABLE
  Added Mikaels patch for partition and ALTER TABLE
  Instead of using 'TABLE_SHARE->is_view' use 'table_flags() & HA_NO_COPY_ON_ALTER
sql/sql_test.cc:
  table_name and table_cache_key are now LEX_STRING's
sql/sql_trigger.cc:
  TABLE_SHARE->db and TABLE_SHARE->table_name are now LEX_STRING's
  safer strxnmov()
  Removed compiler warnings
sql/sql_update.cc:
  Call field->init(TABLE) after field is created
sql/sql_view.cc:
  safer strxnmov()
  Create common TABLE_SHARE object for views to allow us to cache if table is a view
sql/structs.h:
  Added SHOW_TABLE_DEFINITIONS
sql/table.cc:
  Creation and destruct of TABLE_SHARE objects that are common for many TABLE objects
  
  The table opening process now works the following way:
  - Create common TABLE_SHARE object
  - Read the .frm file and unpack it into the TABLE_SHARE object
  - Create a TABLE object based on the information in the TABLE_SHARE
    object and open a handler to the table object
  
  open_table_def() is written in such a way that it should be trival to add parsing of the .frm files in new formats
sql/table.h:
  TABLE objects for the same database table now share a common TABLE_SHARE object
  In TABLE_SHARE the most common strings are now LEX_STRING's
sql/unireg.cc:
  Changed arguments to rea_create_table() to have same order as other functions
  Call field->init(table) for new created fields
sql/unireg.h:
  Added OPEN_VIEW
strings/strxnmov.c:
  Change strxnmov() to always add end \0
  This makes usage of strxnmov() safer as most of MySQL code assumes that strxnmov() will create a null terminated string
2005-11-23 22:45:02 +02:00

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drop table if exists t1,t2,t3,t4,t5,t6;
drop database if exists mysqltest;
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");
create table t3 (a int not null, b char(20), key(a)) engine=MERGE UNION=(t1,t2);
select * from t3;
a b
1 Testing
2 table
3 t1
1 Testing
2 table
3 t2
select * from t3 order by a desc;
a b
3 t1
3 t2
2 table
2 table
1 Testing
1 Testing
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;
create table t3 (a int not null, b char(20), key(a)) engine=MERGE UNION=(test.t1,test.t2);
explain select * from t3 where a < 10;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t3 range a a 4 NULL 18 Using where
explain select * from t3 where a > 10 and a < 20;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t3 range a a 4 NULL 17 Using where
select * from t3 where a = 10;
a b
10 Testing
10 Testing
select * from t3 where a < 10;
a b
1 Testing
1 Testing
2 table
2 table
3 t1
3 t2
4 Testing
4 Testing
5 table
5 table
6 t1
6 t2
7 Testing
7 Testing
8 table
8 table
9 t2
9 t2
select * from t3 where a > 10 and a < 20;
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
explain select a from t3 order by a desc limit 10;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t3 index NULL a 4 NULL 1131 Using index
select a from t3 order by a desc limit 10;
a
699
698
697
696
695
694
693
692
691
690
select a from t3 order by a desc limit 300,10;
a
416
415
415
414
414
413
413
412
412
411
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
show create table t3;
Table Create Table
t3 CREATE TABLE `t3` (
`a` int(11) NOT NULL,
`b` char(20) default NULL,
KEY `a` (`a`)
) 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);
select * from t4;
ERROR HY000: All tables in the MERGE table are not identically defined
alter table t4 add column c int;
ERROR HY000: All tables in the MERGE table are not identically defined
flush tables;
select * from t4;
ERROR HY000: All tables in the MERGE table are not identically defined
create database mysqltest;
create table mysqltest.t6 (a int not null primary key auto_increment, message char(20));
create table t5 (a int not null, b char(20), key(a)) engine=MERGE UNION=(test.t1,mysqltest.t6);
show create table t5;
Table Create Table
t5 CREATE TABLE `t5` (
`a` int(11) NOT NULL,
`b` char(20) default NULL,
KEY `a` (`a`)
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`t1`,`mysqltest`.`t6`)
alter table t5 engine=myisam;
drop table t5, mysqltest.t6;
drop database mysqltest;
drop table t4,t3,t1,t2;
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;
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;
c
test1
test1
test1
test2
test2
test2
select * from t3;
c
test1
test1
test1
test2
test2
test2
delete from t3 where 1=1;
select * from t3;
c
select * from t1;
c
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))
ENGINE=MERGE UNION=(t1,t2);
SELECT * from t3;
incr othr
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;
incr othr
1 10
2 24
4 33
3 53
alter table t3 UNION=(t1);
select count(*) from t3;
count(*)
10
alter table t3 UNION=(t1,t2);
select count(*) from t3;
count(*)
20
alter table t3 ENGINE=MYISAM;
select count(*) from t3;
count(*)
20
drop table t3;
CREATE TABLE t3 (incr int not null, othr int not null, primary key(incr))
ENGINE=MERGE UNION=(t1,t2);
show create table t3;
Table Create Table
t3 CREATE TABLE `t3` (
`incr` int(11) NOT NULL,
`othr` int(11) NOT NULL,
PRIMARY KEY (`incr`)
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`t1`,`t2`)
alter table t3 drop primary key;
show create table t3;
Table Create Table
t3 CREATE TABLE `t3` (
`incr` int(11) NOT NULL,
`othr` int(11) NOT NULL
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`t1`,`t2`)
drop table t3,t2,t1;
create table t1 (a int not null, key(a)) engine=merge;
select * from t1;
a
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));
create table t3 (a int not null, b int not null, key(a,b)) ENGINE=MERGE UNION=(t1,t2);
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;
a b
1 1
1 2
drop table t3,t1,t2;
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));
create table t3 (a int not null, b int not null, key(a,b)) UNION=(t1,t2) INSERT_METHOD=NO;
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;
show create table t3;
Table Create Table
t3 CREATE TABLE `t3` (
`a` int(11) NOT NULL,
`b` int(11) NOT NULL,
KEY `a` (`a`,`b`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1
show create table t4;
Table Create Table
t4 CREATE TABLE `t4` (
`a` int(11) NOT NULL,
`b` int(11) NOT NULL,
KEY `a` (`a`,`b`)
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`t1`,`t2`)
show create table t5;
Table Create Table
t5 CREATE TABLE `t5` (
`a` int(11) NOT NULL,
`b` int(11) NOT NULL auto_increment,
PRIMARY KEY (`a`,`b`)
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 INSERT_METHOD=FIRST UNION=(`t1`,`t2`)
show create table t6;
Table Create Table
t6 CREATE TABLE `t6` (
`a` int(11) NOT NULL,
`b` int(11) NOT NULL auto_increment,
PRIMARY KEY (`a`,`b`)
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 INSERT_METHOD=LAST UNION=(`t1`,`t2`)
insert into t1 values (1,NULL),(1,NULL),(1,NULL),(1,NULL);
insert into t2 values (2,NULL),(2,NULL),(2,NULL),(2,NULL);
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` (
`a` int(11) NOT NULL,
`b` int(11) NOT NULL,
KEY `a` (`a`,`b`)
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`t1`,`t2`,`t3`)
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` (
`a` int(11) NOT NULL,
`b` int(11) NOT NULL,
KEY `a` (`a`,`b`)
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 INSERT_METHOD=FIRST UNION=(`t1`,`t2`,`t3`)
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
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
insert into t1 values (99,NULL);
select * from t4 where a+0 > 90;
a b
99 1
insert t5 values (1,1);
ERROR 23000: Duplicate entry '1-1' for key 1
insert t6 values (2,1);
ERROR 23000: Duplicate entry '2-1' for key 1
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
drop table t6, t5, t4, t3, t2, t1;
CREATE TABLE t1 ( a int(11) NOT NULL default '0', b int(11) NOT NULL default '0', PRIMARY KEY (a,b)) ENGINE=MyISAM;
INSERT INTO t1 VALUES (1,1), (2,1);
CREATE TABLE t2 ( a int(11) NOT NULL default '0', b int(11) NOT NULL default '0', PRIMARY KEY (a,b)) ENGINE=MyISAM;
INSERT INTO t2 VALUES (1,2), (2,2);
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);
select max(b) from t3 where a = 2;
max(b)
2
select max(b) from t1 where a = 2;
max(b)
1
drop table t3,t1,t2;
create table t1 (a int not null);
create table t2 (a int not null);
insert into t1 values (1);
insert into t2 values (2);
create temporary table t3 (a int not null) ENGINE=MERGE UNION=(t1,t2);
select * from t3;
a
1
2
create temporary table t4 (a int not null);
create temporary table t5 (a int not null);
insert into t4 values (1);
insert into t5 values (2);
create temporary table t6 (a int not null) ENGINE=MERGE UNION=(t4,t5);
select * from t6;
a
1
2
drop table t6, t3, t1, t2, t4, t5;
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)
) ENGINE=MyISAM;
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)
) ENGINE=MRG_MyISAM UNION=(t1);
EXPLAIN SELECT * FROM t2 IGNORE INDEX (files) WHERE fileset_id = 2
AND file_code BETWEEN '0000000115' AND '0000000120' LIMIT 1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range PRIMARY PRIMARY 35 NULL 5 Using where
EXPLAIN SELECT * FROM t2 WHERE fileset_id = 2
AND file_code BETWEEN '0000000115' AND '0000000120' LIMIT 1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range PRIMARY,files PRIMARY 35 NULL 5 Using where
EXPLAIN SELECT * FROM t1 WHERE fileset_id = 2
AND file_code BETWEEN '0000000115' AND '0000000120' LIMIT 1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range PRIMARY,files PRIMARY 35 NULL 5 Using where
EXPLAIN SELECT * FROM t2 WHERE fileset_id = 2
AND file_code = '0000000115' LIMIT 1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 ref PRIMARY,files PRIMARY 35 const,const 1 Using where
DROP TABLE t2, t1;
create table t1 (x int, y int, index xy(x, y));
create table t2 (x int, y int, index xy(x, y));
create table t3 (x int, y int, index xy(x, y)) engine=merge union=(t1,t2);
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
1 3
1 2
drop table t1,t2,t3;
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;
ERROR HY000: You can't specify target table 't1' for update in FROM clause
create table t3 engine=merge union=(t1, t2) select * from t2;
ERROR HY000: You can't specify target table 't2' for update in FROM clause
create table t3 engine=merge union=(t1, t2) select (select max(a) from t2);
ERROR HY000: You can't specify target table 't2' for update in FROM clause
drop table t1, t2;
create table t1 (
a double(14,4),
b varchar(10),
index (a,b)
) engine=merge union=(t2,t3);
create table t2 (
a double(14,4),
b varchar(10),
index (a,b)
) engine=myisam;
create table t3 (
a double(14,4),
b varchar(10),
index (a,b)
) engine=myisam;
insert into t2 values ( null, '');
insert into t2 values ( 9999999999.999, '');
insert into t3 select * from t2;
select min(a), max(a) from t1;
min(a) max(a)
9999999999.9990 9999999999.9990
flush tables;
select min(a), max(a) from t1;
min(a) max(a)
9999999999.9990 9999999999.9990
drop table t1, t2, t3;
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
show index from t3;
Table Non_unique Key_name Seq_in_index Column_name Collation Cardinality Sub_part Packed Null Index_type 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
drop table t1, t2, t3;
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;
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