database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-12-24 11:21:21 +03:00
Code Activity

new EXPLAIN

Browse Source 
fixed bug in mysql-test/create-test-result
fixed bug in union-subselect engine
This commit is contained in:
bell@sanja.is.com.ua
2002-09-26 23:08:22 +03:00
parent d9989c635e
commit 46a22a5be7
36 changed files with 607 additions and 457 deletions
Download Patch File Download Diff File Expand all files Collapse all files

23
mysql-test/r/subselect.result
View File

@@ -46,6 +46,13 @@ a b
2 7
3 8
4 8
explain select * from t2 where t2.b=(select a from t3 order by 1 desc limit 1)
union (select * from t4 where t4.b=(select max(t2.a)*4 from t2) order by a);
id select_type table type possible_keys key key_len ref rows Extra
1 FIRST t2 ALL NULL NULL NULL NULL 2 where used
3 UNION t4 ALL NULL NULL NULL NULL 3 where used; Using filesort
4 SUBSELECT t2 ALL NULL NULL NULL NULL 2
2 SUBSELECT t3 ALL NULL NULL NULL NULL 3 Using filesort
select (select a from t3 where a<t2.a*4 order by 1 desc limit 1), a from t2;
(select a from t3 where a<t2.a*4 order by 1 desc limit 1) a
3 1
@@ -54,6 +61,12 @@ select (select t3.a from t3 where a<8 order by 1 desc limit 1), a from
(select * from t2 where a>1) as tt;
(select t3.a from t3 where a<8 order by 1 desc limit 1) a
7 2
explain select (select t3.a from t3 where a<8 order by 1 desc limit 1), a from
(select * from t2 where a>1) as tt;
id select_type table type possible_keys key key_len ref rows Extra
3 DERIVED t2 ALL NULL NULL NULL NULL 2 where used
1 FIRST <derived3> system NULL NULL NULL NULL 1
2 SUBSELECT t3 ALL NULL NULL NULL NULL 3 where used; Using filesort
select * from t1 where t1.a=(select t2.a from t2 where t2.b=(select max(a) from t3) order by 1 desc limit 1);
a
2
@@ -67,6 +80,11 @@ b (select avg(t2.a+(select min(t3.a) from t3 where t3.a >= t4.a)) from t2)
8 7.5000
8 4.5000
9 7.5000
explain select b,(select avg(t2.a+(select min(t3.a) from t3 where t3.a >= t4.a)) from t2) from t4;
id select_type table type possible_keys key key_len ref rows Extra
1 FIRST t4 ALL NULL NULL NULL NULL 3
2 DEPENDENT SUBSELECT t2 ALL NULL NULL NULL NULL 2
3 DEPENDENT SUBSELECT t3 ALL NULL NULL NULL NULL 3 where used
select * from t3 where exists (select * from t2 where t2.b=t3.a);
a
7
@@ -97,6 +115,11 @@ select (select a from t1 where t1.a=t2.a union select a from t5 where t5.a=t2.a)
(select a from t1 where t1.a=t2.a union select a from t5 where t5.a=t2.a) a
NULL 1
2 2
explain select (select a from t1 where t1.a=t2.a union select a from t5 where t5.a=t2.a), a from t2;
id select_type table type possible_keys key key_len ref rows Extra
1 FIRST t2 ALL NULL NULL NULL NULL 2
2 DEPENDENT SUBSELECT t1 system NULL NULL NULL NULL 1 where used
3 DEPENDENT UNION t5 ALL NULL NULL NULL NULL 2 where used
select (select a from t1 where t1.a=t2.a union all select a from t5 where t5.a=t2.a), a from t2;
Subselect return more than 1 record
create table attend (patient_uq int, clinic_uq int, index i1 (clinic_uq));