SET global query_cache_type=ON; SET local query_cache_type=ON; SET SESSION STORAGE_ENGINE = InnoDB; drop table if exists t1,t2,t3; set @save_query_cache_size = @@global.query_cache_size; set GLOBAL query_cache_size = 1355776; flush status; set autocommit=0; create table t1 (a int not null); insert into t1 values (1),(2),(3); select * from t1; a 1 2 3 show status like "Qcache_queries_in_cache"; Variable_name Value Qcache_queries_in_cache 0 drop table t1; commit; set autocommit=1; begin; create table t1 (a int not null); insert into t1 values (1),(2),(3); select * from t1; a 1 2 3 show status like "Qcache_queries_in_cache"; Variable_name Value Qcache_queries_in_cache 1 drop table t1; commit; create table t1 (a int not null); create table t2 (a int not null); create table t3 (a int not null); insert into t1 values (1),(2); insert into t2 values (1),(2); insert into t3 values (1),(2); select * from t1; a 1 2 select * from t2; a 1 2 select * from t3; a 1 2 show status like "Qcache_queries_in_cache"; Variable_name Value Qcache_queries_in_cache 3 show status like "Qcache_hits"; Variable_name Value Qcache_hits 0 begin; select * from t1; a 1 2 select * from t2; a 1 2 select * from t3; a 1 2 show status like "Qcache_queries_in_cache"; Variable_name Value Qcache_queries_in_cache 6 show status like "Qcache_hits"; Variable_name Value Qcache_hits 0 insert into t1 values (3); insert into t2 values (3); insert into t1 values (4); select * from t1; a 1 2 3 4 select * from t2; a 1 2 3 select * from t3; a 1 2 show status like "Qcache_queries_in_cache"; Variable_name Value Qcache_queries_in_cache 2 show status like "Qcache_hits"; Variable_name Value Qcache_hits 1 commit; show status like "Qcache_queries_in_cache"; Variable_name Value Qcache_queries_in_cache 2 drop table t3,t2,t1; CREATE TABLE t1 (id int(11) NOT NULL auto_increment, PRIMARY KEY (id)); select count(*) from t1; count(*) 0 insert into t1 (id) values (0); select count(*) from t1; count(*) 1 drop table t1; CREATE TABLE t1 ( id int(10) NOT NULL auto_increment, a varchar(25) default NULL, PRIMARY KEY (id), UNIQUE KEY a (a)); CREATE TABLE t2 ( id int(10) NOT NULL auto_increment, b varchar(25) default NULL, PRIMARY KEY (id), UNIQUE KEY b (b)); CREATE TABLE t3 ( id int(10) NOT NULL auto_increment, t1_id int(10) NOT NULL default '0', t2_id int(10) NOT NULL default '0', state int(11) default NULL, PRIMARY KEY (id), UNIQUE KEY t1_id (t1_id,t2_id), KEY t2_id (t2_id,t1_id), CONSTRAINT `t3_ibfk_1` FOREIGN KEY (`t1_id`) REFERENCES `t1` (`id`), CONSTRAINT `t3_ibfk_2` FOREIGN KEY (`t2_id`) REFERENCES `t2` (`id`)); INSERT INTO t1 VALUES (1,'me'); INSERT INTO t2 VALUES (1,'you'); INSERT INTO t3 VALUES (2,1,1,2); delete from t3 where t1_id = 1 and t2_id = 1; select t1.* from t1, t2, t3 where t3.state & 1 = 0 and t3.t1_id = t1.id and t3.t2_id = t2.id and t1.id = 1 order by t1.a asc; id a begin; insert into t3 VALUES ( NULL, 1, 1, 2 ); insert into t3 VALUES ( NULL, 1, 1, 2 ); ERROR 23000: Duplicate entry '1-1' for key 't1_id' commit; select t1.* from t1, t2, t3 where t3.state & 1 = 0 and t3.t1_id = t1.id and t3.t2_id = t2.id and t1.id = 1 order by t1.a asc; id a 1 me drop table t3,t2,t1; connect connection1,localhost,root,,; SET SESSION STORAGE_ENGINE = InnoDB; SET @@autocommit=1; connection default; SHOW VARIABLES LIKE 'have_query_cache'; Variable_name Value have_query_cache YES SET GLOBAL query_cache_size = 204800; flush status; SET @@autocommit=1; SET SESSION STORAGE_ENGINE = InnoDB; CREATE TABLE t2 (s1 int, s2 varchar(1000), key(s1)); INSERT INTO t2 VALUES (1,repeat('a',10)),(2,repeat('a',10)),(3,repeat('a',10)),(4,repeat('a',10)); COMMIT; START TRANSACTION; SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w'; count(*) 0 UPDATE t2 SET s2 = 'w' WHERE s1 = 3; SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w'; count(*) 1 show status like "Qcache_queries_in_cache"; Variable_name Value Qcache_queries_in_cache 0 connection connection1; START TRANSACTION; SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w'; count(*) 0 INSERT INTO t2 VALUES (5,'w'); SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w'; count(*) 1 COMMIT; SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w'; count(*) 1 show status like "Qcache_queries_in_cache"; Variable_name Value Qcache_queries_in_cache 0 connection default; SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w'; count(*) 1 COMMIT; show status like "Qcache_queries_in_cache"; Variable_name Value Qcache_queries_in_cache 0 SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w'; count(*) 2 show status like "Qcache_queries_in_cache"; Variable_name Value Qcache_queries_in_cache 1 connection connection1; SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w'; count(*) 2 START TRANSACTION; SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w'; count(*) 2 INSERT INTO t2 VALUES (6,'w'); SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w'; count(*) 3 connection default; SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w'; count(*) 2 START TRANSACTION; SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w'; count(*) 2 DELETE from t2 WHERE s1=3; SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w'; count(*) 1 COMMIT; connection connection1; COMMIT; SELECT sql_cache count(*) FROM t2 WHERE s2 = 'w'; count(*) 2 show status like "Qcache_queries_in_cache"; Variable_name Value Qcache_queries_in_cache 1 show status like "Qcache_hits"; Variable_name Value Qcache_hits 1 disconnect connection1; connection default; set @@global.query_cache_size = @save_query_cache_size; drop table t2; SET global query_cache_type=default; CREATE TABLE t1 (a INT) ENGINE=InnoDB; BEGIN; INSERT INTO t1 VALUES(1); ROLLBACK WORK AND CHAIN NO RELEASE; SELECT a FROM t1; a ROLLBACK WORK AND CHAIN NO RELEASE; SELECT a FROM t1; a ROLLBACK; DROP TABLE t1;