Current Path : /home/usr.opt/mysql57/mysql-test/r/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
Current File : //home/usr.opt/mysql57/mysql-test/r/join_optimizer.result |
drop table if exists t0,t1,t2,t3; # # BUG#38049 incorrect rows estimations with references from preceding table # create table t0 (a int); insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9); create table t1 (a varchar(32)); insert into t1 values ('owner'),('requester'),('admincc'),('cc'); CREATE TABLE t2 ( id int(11) NOT NULL, type varchar(32) default NULL, PRIMARY KEY (id) ); insert into t2 values (1,'owner'), (2,'admincc'); CREATE TABLE t3 ( id int(11) NOT NULL, domain varchar(32) default NULL, type varchar(32) default NULL, PRIMARY KEY (id) ); set @domain='system'; set @pk=0; INSERT INTO t3 select @pk:=@pk+1, 'system', t1.a from t1; INSERT INTO t3 select @pk:=@pk+1, 'queue', t1.a from t1, t0 where t0.a<3; INSERT INTO t3 select @pk:=@pk+1, 'ticket', t1.a from t1, t0 A, t0 B, t0 C; CREATE INDEX groups_d ON t3(domain); CREATE INDEX groups_t ON t3(type); CREATE INDEX groups_td ON t3(type, domain); CREATE INDEX groups_dt ON t3(domain, type); For table g this must use ref(groups_dt) and #rows should be around 15 and not 335: explain SELECT STRAIGHT_JOIN g.id FROM t2 a, t3 g USE INDEX(groups_dt) WHERE g.domain = 'queue' AND g.type = a.type; id select_type table type possible_keys key key_len ref rows Extra 1 SIMPLE a ALL NULL NULL NULL NULL 2 Using where 1 SIMPLE g ref groups_dt groups_dt 70 const,test.a.type 13 Using index condition drop table t0,t1,t2,t3; # # BUG#47217 Lost optimization caused slowdown & wrong result. # CREATE TABLE t1 (pk INT, v VARCHAR(2), PRIMARY KEY(pk)); CREATE INDEX ix1 ON t1(v); CREATE TABLE t2 (pk INT, v VARCHAR(2), PRIMARY KEY(pk)); CREATE INDEX ix2 ON t2(v); INSERT INTO t1 VALUES (1,'a'),(2,NULL); INSERT INTO t2 VALUES (1,NULL); EXPLAIN SELECT * FROM t1 JOIN t2 ON t1.v = t2.v ORDER BY 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 EXPLAIN SELECT * FROM t1 JOIN t2 ON t1.v = t2.v; 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 INSERT INTO t1 VALUES (3,'b'),(4,NULL),(5,'c'),(6,'cc'),(7,'d'), (8,'dd'),(9,'e'),(10,'ee'); INSERT INTO t2 VALUES (2,NULL); FLUSH STATUS; SELECT * FROM t1 JOIN t2 ON t1.v = t2.v WHERE t2.v IS NULL ORDER BY 1; pk v pk v SHOW STATUS LIKE 'Handler_read_%'; Variable_name Value Handler_read_first 0 Handler_read_key 1 Handler_read_last 0 Handler_read_next 0 Handler_read_prev 0 Handler_read_rnd 0 Handler_read_rnd_next 1 DROP TABLE t1, t2; # End of test for bug#47217