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e42c980967
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
148 lines
4.2 KiB
Text
148 lines
4.2 KiB
Text
drop table if exists t1,t2;
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drop view if exists v1;
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CREATE TABLE t1 (c int not null, d char (10) not null);
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insert into t1 values(1,""),(2,"a"),(3,"b");
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CREATE TEMPORARY TABLE t1 (a int not null, b char (10) not null);
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insert into t1 values(4,"e"),(5,"f"),(6,"g");
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alter table t1 rename t2;
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select * from t1;
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c d
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1
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2 a
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3 b
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select * from t2;
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a b
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4 e
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5 f
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6 g
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CREATE TABLE t2 (x int not null, y int not null);
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alter table t2 rename t1;
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select * from t1;
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a b
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4 e
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5 f
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6 g
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create TEMPORARY TABLE t2 engine=heap select * from t1;
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create TEMPORARY TABLE IF NOT EXISTS t2 (a int) engine=heap;
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Warnings:
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Note 1050 Table 't2' already exists
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CREATE TEMPORARY TABLE t1 (a int not null, b char (10) not null);
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ERROR 42S01: Table 't1' already exists
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ALTER TABLE t1 RENAME t2;
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ERROR 42S01: Table 't2' already exists
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select * from t2;
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a b
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4 e
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5 f
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6 g
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alter table t2 add primary key (a,b);
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drop table t1,t2;
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select * from t1;
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c d
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1
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2 a
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3 b
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drop table t2;
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create temporary table t1 select *,2 as "e" from t1;
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select * from t1;
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c d e
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1 2
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2 a 2
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3 b 2
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drop table t1;
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drop table t1;
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CREATE TABLE t1 (pkCrash INTEGER PRIMARY KEY,strCrash VARCHAR(255));
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INSERT INTO t1 ( pkCrash, strCrash ) VALUES ( 1, '1');
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SELECT CONCAT_WS(pkCrash, strCrash) FROM t1;
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CONCAT_WS(pkCrash, strCrash)
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1
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drop table t1;
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create temporary table t1 select 1 as 'x';
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drop table t1;
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CREATE TABLE t1 (x INT);
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INSERT INTO t1 VALUES (1), (2), (3);
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CREATE TEMPORARY TABLE tmp SELECT *, NULL FROM t1;
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drop table t1;
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create temporary table t1 (id int(10) not null unique);
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create temporary table t2 (id int(10) not null primary key,
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val int(10) not null);
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insert into t1 values (1),(2),(4);
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insert into t2 values (1,1),(2,1),(3,1),(4,2);
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select one.id, two.val, elt(two.val,'one','two') from t1 one, t2 two where two.id=one.id order by one.id;
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id val elt(two.val,'one','two')
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1 1 one
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2 1 one
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4 2 two
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drop table t1,t2;
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create temporary table t1 (a int not null);
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insert into t1 values (1),(1);
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alter table t1 add primary key (a);
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ERROR 23000: Duplicate entry '1' for key 1
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drop table t1;
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CREATE TABLE t1 (
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d datetime default NULL
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) ENGINE=MyISAM;
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INSERT INTO t1 VALUES ('2002-10-24 14:50:32'),('2002-10-24 14:50:33'),('2002-10-24 14:50:34'),('2002-10-24 14:50:34'),('2002-10-24 14:50:34'),('2002-10-24 14:50:35'),('2002-10-24 14:50:35'),('2002-10-24 14:50:35'),('2002-10-24 14:50:35'),('2002-10-24 14:50:36'),('2002-10-24 14:50:36'),('2002-10-24 14:50:36'),('2002-10-24 14:50:36'),('2002-10-24 14:50:37'),('2002-10-24 14:50:37'),('2002-10-24 14:50:37'),('2002-10-24 14:50:37'),('2002-10-24 14:50:38'),('2002-10-24 14:50:38'),('2002-10-24 14:50:38'),('2002-10-24 14:50:39'),('2002-10-24 14:50:39'),('2002-10-24 14:50:39'),('2002-10-24 14:50:39'),('2002-10-24 14:50:40'),('2002-10-24 14:50:40'),('2002-10-24 14:50:40');
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flush status;
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select * from t1 group by d;
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d
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2002-10-24 14:50:32
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2002-10-24 14:50:33
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2002-10-24 14:50:34
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2002-10-24 14:50:35
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2002-10-24 14:50:36
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2002-10-24 14:50:37
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2002-10-24 14:50:38
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2002-10-24 14:50:39
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2002-10-24 14:50:40
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show status like "created_tmp%tables";
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Variable_name Value
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Created_tmp_disk_tables 0
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Created_tmp_tables 2
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drop table t1;
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create temporary table v1 as select 'This is temp. table' A;
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create view v1 as select 'This is view' A;
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select * from v1;
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A
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This is temp. table
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show create table v1;
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Table Create Table
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v1 CREATE TEMPORARY TABLE `v1` (
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`A` varchar(19) NOT NULL default ''
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) ENGINE=MyISAM DEFAULT CHARSET=latin1
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show create view v1;
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View Create View
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v1 CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v1` AS select _latin1'This is view' AS `A`
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drop view v1;
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select * from v1;
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A
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This is temp. table
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create view v1 as select 'This is view again' A;
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select * from v1;
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A
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This is temp. table
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drop table v1;
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select * from v1;
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A
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This is view again
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drop view v1;
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create table t1 (a int, b int, index(a), index(b));
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create table t2 (c int auto_increment, d varchar(255), primary key (c));
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insert into t1 values (3,1),(3,2);
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insert into t2 values (NULL, 'foo'), (NULL, 'bar');
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select d, c from t1 left join t2 on b = c where a = 3 order by d;
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d c
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bar 2
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foo 1
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drop table t1, t2;
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create temporary table t1 (a int);
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insert into t1 values (4711);
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select * from t1;
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a
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4711
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truncate t1;
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insert into t1 values (42);
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select * from t1;
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a
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42
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drop table t1;
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