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MDEV-29350 Crash when IN predicand is used in eliminated GROUP BY clause

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This bug affected some queries with an IN/ALL/ANY predicand or an EXISTS
predicate whose subquery contained a GROUP BY clause that could be
eliminated. If this clause used a IN/ALL/ANY predicand whose left operand
was a single-value subquery then execution of the query caused a crash of
the server after invokation of remove_redundant_subquery_clauses().
The crash was caused by an attempt to exclude the unit for the single-value
subquery from the query tree for the second time by the function
Item_subselect::eliminate_subselect_processor().

This bug had been masked by the bug MDEV-28617 until a fix for the latter
that properly excluded units was pushed into 10.3.

Approved by Oleksandr Byelkin <sanja@mariadb.com>
This commit is contained in:
Igor Babaev
2022-08-24 11:07:09 -07:00
parent d1a80c42ee
commit 94e3f02db7
3 changed files with 192 additions and 1 deletions
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116
mysql-test/main/subselect4.result
View File

@ -3038,4 +3038,120 @@ a
3 3
2 2
drop table t1,t2,t3; drop table t1,t2,t3;
#
# MDEV-29139: Redundant IN/ALL/ANY predicand in GROUP BY clause of
# IN/ALL/ANY/EXISTS subquery
#
create table t1 (a int);
create table t2 (b int);
create table t3 (c int);
create table t4 (d int);
insert into t1 values (3), (1);
insert into t2 values (3), (2);
insert into t3 values (4), (2);
insert into t4 values (1), (7);
explain extended select b from t2
where exists (select c from t3
group by (select a from t1 where a = 1) in (select d from t4));
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t2 ALL NULL NULL NULL NULL 2 100.00
2 SUBQUERY t3 ALL NULL NULL NULL NULL 2 100.00
Warnings:
Note 1003 /* select#1 */ select `test`.`t2`.`b` AS `b` from `test`.`t2` where 1
select b from t2
where exists (select c from t3
group by (select a from t1 where a = 1) in (select d from t4));
b
3
2
prepare stmt from "select b from t2
where exists (select c from t3
group by (select a from t1 where a = 1) in (select d from t4))";
execute stmt;
b
3
2
execute stmt;
b
3
2
deallocate prepare stmt;
explain extended select b from t2
where exists (select c from t3
group by (select a from t1 where a = 1) >=
any (select d from t4));
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t2 ALL NULL NULL NULL NULL 2 100.00
2 SUBQUERY t3 ALL NULL NULL NULL NULL 2 100.00
Warnings:
Note 1003 /* select#1 */ select `test`.`t2`.`b` AS `b` from `test`.`t2` where 1
select b from t2
where exists (select c from t3
group by (select a from t1 where a = 1) >=
any (select d from t4));
b
3
2
explain extended select b from t2
where exists (select c from t3
group by (select a from t1 where a = 1) <
all (select d from t4));
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t2 ALL NULL NULL NULL NULL 2 100.00
2 SUBQUERY t3 ALL NULL NULL NULL NULL 2 100.00
Warnings:
Note 1003 /* select#1 */ select `test`.`t2`.`b` AS `b` from `test`.`t2` where 1
select b from t2
where exists (select c from t3
group by (select a from t1 where a = 1) <
all (select d from t4));
b
3
2
explain extended select b from t2
where b in (select c from t3
group by (select a from t1 where a = 1) in (select d from t4));
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t2 ALL NULL NULL NULL NULL 2 100.00
1 PRIMARY <subquery2> eq_ref distinct_key distinct_key 4 func 1 100.00
2 MATERIALIZED t3 ALL NULL NULL NULL NULL 2 100.00
Warnings:
Note 1003 select `test`.`t2`.`b` AS `b` from `test`.`t2` semi join (`test`.`t3`) where 1
select b from t2
where b in (select c from t3
group by (select a from t1 where a = 1) in (select d from t4));
b
2
explain extended select b from t2
where b >= any (select c from t3
group by (select a from t1 where a = 1) in
(select d from t4));
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t2 ALL NULL NULL NULL NULL 2 100.00 Using where
2 SUBQUERY t3 ALL NULL NULL NULL NULL 2 100.00
Warnings:
Note 1003 /* select#1 */ select `test`.`t2`.`b` AS `b` from `test`.`t2` where <nop>(<in_optimizer>(`test`.`t2`.`b`,(/* select#2 */ select min(`test`.`t3`.`c`) from `test`.`t3`) <= <cache>(`test`.`t2`.`b`)))
select b from t2
where b >= any (select c from t3
group by (select a from t1 where a = 1) in
(select d from t4));
b
3
2
explain extended select b from t2
where b <= all (select c from t3
group by (select a from t1 where a = 1) in
(select d from t4));
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t2 ALL NULL NULL NULL NULL 2 100.00 Using where
2 SUBQUERY t3 ALL NULL NULL NULL NULL 2 100.00
Warnings:
Note 1003 /* select#1 */ select `test`.`t2`.`b` AS `b` from `test`.`t2` where <not>(<in_optimizer>(`test`.`t2`.`b`,<min>(/* select#2 */ select `test`.`t3`.`c` from `test`.`t3`) < <cache>(`test`.`t2`.`b`)))
select b from t2
where b <= all (select c from t3
group by (select a from t1 where a = 1) in
(select d from t4));
b
2
drop table t1,t2,t3,t4;
# End of 10.3 tests # End of 10.3 tests

74
mysql-test/main/subselect4.test
View File

@ -2477,4 +2477,78 @@ eval $q3;
drop table t1,t2,t3; drop table t1,t2,t3;
--echo #
--echo # MDEV-29139: Redundant IN/ALL/ANY predicand in GROUP BY clause of
--echo # IN/ALL/ANY/EXISTS subquery
--echo #
create table t1 (a int);
create table t2 (b int);
create table t3 (c int);
create table t4 (d int);
insert into t1 values (3), (1);
insert into t2 values (3), (2);
insert into t3 values (4), (2);
insert into t4 values (1), (7);
let $q1=
select b from t2
where exists (select c from t3
group by (select a from t1 where a = 1) in (select d from t4));
eval explain extended $q1;
eval $q1;
eval prepare stmt from "$q1";
execute stmt;
execute stmt;
deallocate prepare stmt;
let $q2=
select b from t2
where exists (select c from t3
group by (select a from t1 where a = 1) >=
any (select d from t4));
eval explain extended $q2;
eval $q2;
let $q3=
select b from t2
where exists (select c from t3
group by (select a from t1 where a = 1) <
all (select d from t4));
eval explain extended $q3;
eval $q3;
let $q4=
select b from t2
where b in (select c from t3
group by (select a from t1 where a = 1) in (select d from t4));
eval explain extended $q4;
eval $q4;
let $q5=
select b from t2
where b >= any (select c from t3
group by (select a from t1 where a = 1) in
(select d from t4));
eval explain extended $q5;
eval $q5;
let $q6=
select b from t2
where b <= all (select c from t3
group by (select a from t1 where a = 1) in
(select d from t4));
eval explain extended $q6;
eval $q6;
drop table t1,t2,t3,t4;
--echo # End of 10.3 tests --echo # End of 10.3 tests

3
sql/item_subselect.cc
View File

@ -379,7 +379,8 @@ bool Item_subselect::mark_as_eliminated_processor(void *arg)
bool Item_subselect::eliminate_subselect_processor(void *arg) bool Item_subselect::eliminate_subselect_processor(void *arg)
{ {
unit->item= NULL; unit->item= NULL;
unit->exclude(); if (!unit->is_excluded())
unit->exclude();
eliminated= TRUE; eliminated= TRUE;
return FALSE; return FALSE;
} }