mirror of
https://github.com/MariaDB/server.git
synced 2025-07-29 05:21:33 +03:00
MDEV-30538 Plans for SELECT and multi-table UPDATE/DELETE unexpectedly differ
This patch allowed transformation of EXISTS subqueries into equivalent IN predicands at the top level of WHERE conditions for multi-table UPDATE and DELETE statements. There was no reason to prohibit the transformation for such statements. The transformation provides more opportunities of using semi-join optimizations. Approved by Oleksandr Byelkin <sanja@mariadb.com>
This commit is contained in:
Igor Babaev
@ -1251,3 +1251,123 @@ EXPLAIN
|
||||
}
|
||||
}
|
||||
DROP TABLES t1, t2;
|
||||
# End of 10.3 tests
|
||||
#
|
||||
# MDEV-28538: multi-table UPDATE/DELETE with possible exists-to-in
|
||||
#
|
||||
create table t1 (c1 int, c2 int, c3 int, index idx(c2));
|
||||
insert into t1 values
|
||||
(1,1,1),(3,2,2),(1,3,3),
|
||||
(2,1,4),(2,2,5),(4,3,6),
|
||||
(2,4,7),(2,5,8);
|
||||
create table t2 (c1 int, c2 int, c3 int, index idx(c2));
|
||||
insert into t2 values
|
||||
(1,7,1),(1,8,2),(1,3,3),
|
||||
(2,1,4),(2,2,5),(2,3,6),
|
||||
(2,4,7),(2,5,8);
|
||||
create table t3 (c1 int, c2 int, c3 int, index idx(c2));
|
||||
insert into t3 values
|
||||
(1,1,1),(1,2,2),(1,3,3),
|
||||
(2,1,4),(2,2,5),(2,3,6),
|
||||
(2,4,7),(2,5,8);
|
||||
insert into t3 select c1+1, c2+2, c3 from t3;
|
||||
insert into t3 select c1, c2+2, c3 from t3;
|
||||
analyze table t1,t2,t3 persistent for all;
|
||||
Table Op Msg_type Msg_text
|
||||
test.t1 analyze status Engine-independent statistics collected
|
||||
test.t1 analyze status OK
|
||||
test.t2 analyze status Engine-independent statistics collected
|
||||
test.t2 analyze status OK
|
||||
test.t3 analyze status Engine-independent statistics collected
|
||||
test.t3 analyze status OK
|
||||
explain select * from t1,t3
|
||||
where t1.c2 = t3.c2 and
|
||||
t1.c1 > 1 and
|
||||
exists (select 'X' from t2 where t2.c1 = t1.c1 and t2.c2 > 4);
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 PRIMARY t1 ALL idx NULL NULL NULL 8 Using where
|
||||
1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 4 func 1
|
||||
1 PRIMARY t3 ref idx idx 5 test.t1.c2 3
|
||||
2 MATERIALIZED t2 range idx idx 5 NULL 3 Using index condition; Using where
|
||||
explain delete from t1 using t1,t3
|
||||
where t1.c2 = t3.c2 and
|
||||
t1.c1 > 1 and
|
||||
exists (select 'X' from t2 where t2.c1 = t1.c1 and t2.c2 > 4);
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 PRIMARY t1 ALL idx NULL NULL NULL 8 Using where
|
||||
1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 4 func 1
|
||||
1 PRIMARY t3 ref idx idx 5 test.t1.c2 3 Using index
|
||||
2 MATERIALIZED t2 range idx idx 5 NULL 3 Using where
|
||||
explain update t1,t3 set t1.c1 = t1.c1+10
|
||||
where t1.c2 = t3.c2 and
|
||||
t1.c1 > 1 and
|
||||
exists (select 'X' from t2 where t2.c1 = t1.c1 and t2.c2 > 4);
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 PRIMARY t1 ALL idx NULL NULL NULL 8 Using where
|
||||
1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 4 func 1
|
||||
1 PRIMARY t3 ref idx idx 5 test.t1.c2 3 Using index
|
||||
2 MATERIALIZED t2 range idx idx 5 NULL 3 Using where
|
||||
create table t as select * from t1;
|
||||
select * from t1,t3
|
||||
where t1.c2 = t3.c2 and
|
||||
t1.c1 > 1 and
|
||||
exists (select 'X' from t2 where t2.c1 = t1.c1 and t2.c2 > 4);
|
||||
c1 c2 c3 c1 c2 c3
|
||||
2 1 4 1 1 1
|
||||
2 1 4 2 1 4
|
||||
2 2 5 1 2 2
|
||||
2 2 5 2 2 5
|
||||
2 4 7 2 4 7
|
||||
2 4 7 2 4 2
|
||||
2 4 7 3 4 5
|
||||
2 4 7 1 4 2
|
||||
2 4 7 2 4 5
|
||||
2 5 8 2 5 8
|
||||
2 5 8 2 5 3
|
||||
2 5 8 3 5 6
|
||||
2 5 8 1 5 3
|
||||
2 5 8 2 5 6
|
||||
2 5 8 2 5 1
|
||||
2 5 8 3 5 4
|
||||
select * from t1;
|
||||
c1 c2 c3
|
||||
1 1 1
|
||||
3 2 2
|
||||
1 3 3
|
||||
2 1 4
|
||||
2 2 5
|
||||
4 3 6
|
||||
2 4 7
|
||||
2 5 8
|
||||
delete from t1 using t1,t3
|
||||
where t1.c2 = t3.c2 and
|
||||
t1.c1 > 1 and
|
||||
exists (select 'X' from t2 where t2.c1 = t1.c1 and t2.c2 > 4);
|
||||
select * from t1;
|
||||
c1 c2 c3
|
||||
1 1 1
|
||||
3 2 2
|
||||
1 3 3
|
||||
4 3 6
|
||||
truncate table t1;
|
||||
insert into t1 select * from t;
|
||||
analyze table t1 persistent for all;
|
||||
Table Op Msg_type Msg_text
|
||||
test.t1 analyze status Engine-independent statistics collected
|
||||
test.t1 analyze status Table is already up to date
|
||||
update t1,t3 set t1.c1 = t1.c1+10
|
||||
where t1.c2 = t3.c2 and
|
||||
t1.c1 > 1 and
|
||||
exists (select 'X' from t2 where t2.c1 = t1.c1 and t2.c2 > 4);
|
||||
select * from t1;
|
||||
c1 c2 c3
|
||||
1 1 1
|
||||
3 2 2
|
||||
1 3 3
|
||||
12 1 4
|
||||
12 2 5
|
||||
4 3 6
|
||||
12 4 7
|
||||
12 5 8
|
||||
drop table t1,t2,t3,t;
|
||||
# End of 10.4 tests
|
||||
|
||||
@ -1130,3 +1130,73 @@ EXPLAIN FORMAT=JSON UPDATE t2 JOIN t1 USING(a) SET t2.part=2 WHERE t2.part=1 AND
|
||||
EXPLAIN FORMAT=JSON UPDATE t2 JOIN t1 USING(a) SET t2.part=3 WHERE t2.part=2 AND t1.part=2;
|
||||
|
||||
DROP TABLES t1, t2;
|
||||
|
||||
--echo # End of 10.3 tests
|
||||
|
||||
--echo #
|
||||
--echo # MDEV-28538: multi-table UPDATE/DELETE with possible exists-to-in
|
||||
--echo #
|
||||
|
||||
create table t1 (c1 int, c2 int, c3 int, index idx(c2));
|
||||
insert into t1 values
|
||||
(1,1,1),(3,2,2),(1,3,3),
|
||||
(2,1,4),(2,2,5),(4,3,6),
|
||||
(2,4,7),(2,5,8);
|
||||
|
||||
create table t2 (c1 int, c2 int, c3 int, index idx(c2));
|
||||
insert into t2 values
|
||||
(1,7,1),(1,8,2),(1,3,3),
|
||||
(2,1,4),(2,2,5),(2,3,6),
|
||||
(2,4,7),(2,5,8);
|
||||
|
||||
create table t3 (c1 int, c2 int, c3 int, index idx(c2));
|
||||
insert into t3 values
|
||||
(1,1,1),(1,2,2),(1,3,3),
|
||||
(2,1,4),(2,2,5),(2,3,6),
|
||||
(2,4,7),(2,5,8);
|
||||
insert into t3 select c1+1, c2+2, c3 from t3;
|
||||
insert into t3 select c1, c2+2, c3 from t3;
|
||||
|
||||
analyze table t1,t2,t3 persistent for all;
|
||||
|
||||
let $c=
|
||||
t1.c2 = t3.c2 and
|
||||
t1.c1 > 1 and
|
||||
exists (select 'X' from t2 where t2.c1 = t1.c1 and t2.c2 > 4);
|
||||
|
||||
let $q1=
|
||||
select * from t1,t3
|
||||
where $c;
|
||||
|
||||
eval explain $q1;
|
||||
|
||||
let $q2=
|
||||
delete from t1 using t1,t3
|
||||
where $c;
|
||||
|
||||
eval explain $q2;
|
||||
|
||||
let $q3=
|
||||
update t1,t3 set t1.c1 = t1.c1+10
|
||||
where $c;
|
||||
|
||||
eval explain $q3;
|
||||
|
||||
create table t as select * from t1;
|
||||
|
||||
eval $q1;
|
||||
select * from t1;
|
||||
|
||||
eval $q2;
|
||||
select * from t1;
|
||||
|
||||
truncate table t1;
|
||||
insert into t1 select * from t;
|
||||
analyze table t1 persistent for all;
|
||||
|
||||
eval $q3;
|
||||
select * from t1;
|
||||
|
||||
drop table t1,t2,t3,t;
|
||||
|
||||
--echo # End of 10.4 tests
|
||||
|
||||
@ -76,7 +76,8 @@ rollback;
|
||||
explain update t1 set c1=0 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 > 3;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 PRIMARY t1 ALL NULL NULL NULL NULL 8 Using where
|
||||
2 DEPENDENT SUBQUERY a ALL NULL NULL NULL NULL 8 Using where
|
||||
1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 4 func 1
|
||||
2 MATERIALIZED a ALL NULL NULL NULL NULL 8
|
||||
start transaction;
|
||||
update t1 set c1=c1+10 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 >= 3;
|
||||
affected rows: 4
|
||||
@ -317,7 +318,8 @@ rollback;
|
||||
explain update t1 set c1=0 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 > 3;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 PRIMARY t1 range t1_c2 t1_c2 5 NULL 2 Using where
|
||||
2 DEPENDENT SUBQUERY a ref t1_c2 t1_c2 5 test.t1.c2 4 Using index
|
||||
1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 4 func 1
|
||||
2 MATERIALIZED a range t1_c2 t1_c2 5 NULL 2 Using where; Using index
|
||||
start transaction;
|
||||
update t1 set c1=c1+10 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 >= 3;
|
||||
affected rows: 4
|
||||
@ -558,7 +560,8 @@ rollback;
|
||||
explain update t1 set c1=0 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 > 3;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 PRIMARY t1 range t1_c2 t1_c2 5 NULL 2 Using where
|
||||
2 DEPENDENT SUBQUERY a ref t1_c2 t1_c2 5 test.t1.c2 1 Using index
|
||||
1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 4 func 1
|
||||
2 MATERIALIZED a range t1_c2 t1_c2 5 NULL 2 Using where; Using index
|
||||
start transaction;
|
||||
update t1 set c1=c1+10 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 >= 3;
|
||||
affected rows: 4
|
||||
@ -800,7 +803,8 @@ rollback;
|
||||
explain update t1 set c1=0 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 > 3;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 PRIMARY t1 range t1_c2 t1_c2 5 NULL 2 Using where
|
||||
2 DEPENDENT SUBQUERY a ref t1_c2 t1_c2 5 test.t1.c2 1 Using index
|
||||
1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 4 func 1
|
||||
2 MATERIALIZED a range t1_c2 t1_c2 5 NULL 2 Using where; Using index
|
||||
start transaction;
|
||||
update t1 set c1=c1+10 where exists (select 'X' from t1 a where a.c2 = t1.c2) and c2 >= 3;
|
||||
affected rows: 4
|
||||
|
||||
@ -2825,7 +2825,9 @@ bool Item_exists_subselect::select_prepare_to_be_in()
|
||||
bool trans_res= FALSE;
|
||||
DBUG_ENTER("Item_exists_subselect::select_prepare_to_be_in");
|
||||
if (!optimizer &&
|
||||
thd->lex->sql_command == SQLCOM_SELECT &&
|
||||
(thd->lex->sql_command == SQLCOM_SELECT ||
|
||||
thd->lex->sql_command == SQLCOM_UPDATE_MULTI ||
|
||||
thd->lex->sql_command == SQLCOM_DELETE_MULTI) &&
|
||||
!unit->first_select()->is_part_of_union() &&
|
||||
optimizer_flag(thd, OPTIMIZER_SWITCH_EXISTS_TO_IN) &&
|
||||
(is_top_level_item() ||
|
||||
|
||||
Reference in New Issue
Block a user