database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2026-01-06 05:22:24 +03:00
Code Activity

Optimisation if simple IN subselect with primary index

Browse Source 
(SCRUM) (part of WL#818)
This commit is contained in:
bell@sanja.is.com.ua
2003-07-07 18:40:19 +03:00
parent 7ad5331768
commit 6348e63f62
7 changed files with 177 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
mysql-test/r/subselect.result
View File

@@ -1226,7 +1226,15 @@ a
explain select * from t2 where t2.a in (select a from t1);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 index NULL PRIMARY 4 NULL 4 Using where; Using index
2 DEPENDENT SUBQUERY t1 eq_ref PRIMARY PRIMARY 4 func 1 Using where; Using index
2 DEPENDENT SUBQUERY t1 simple_in PRIMARY PRIMARY 4 func 1 Using index
select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
a
2
4
explain select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 index NULL PRIMARY 4 NULL 4 Using where; Using index
2 DEPENDENT SUBQUERY t1 simple_in PRIMARY PRIMARY 4 func 1 Using index; Using where
select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
a
2

2
mysql-test/t/subselect.test
View File

@@ -819,6 +819,8 @@ insert into t2 values (2), (3), (4), (5);
insert into t3 values (10,3), (20,4), (30,5);
select * from t2 where t2.a in (select a from t1);
explain select * from t2 where t2.a in (select a from t1);
select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
explain select * from t2 where t2.a in (select a from t1 where t1.b <> 30);
select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
explain select * from t2 where t2.a in (select t1.a from t1,t3 where t1.b=t3.a);
drop table t1, t2, t3;