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MDEV-36389 Incorrect query results for an indexed text column

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Fixes a scenario where an IN subquery returned the wrong result
because the pushed WHERE clause was not retained for downstream
result filtering.  For example:
  CREATE TABLE t1 (c1 TEXT, UNIQUE (c1(1)));
  INSERT INTO t1 (c1) VALUES ('a');
  SELECT 'abc' IN (SELECT c1 FROM t1);
Internally, he 'abc' IN subquery condition becomes the constant
condition:
  'abc' = t1.c1 or t1.c1 is null
Prior to this patch, this condition was incorrectly removed when
converting the subquery engine to an index lookup-based engine.
Now eligible conditions are preserved during such engine rewrites.
This commit is contained in:
Sergei Petrunia
2025-07-23 15:40:53 +03:00
committed by Dave Gosselin
parent 3109d994eb
commit a52362b90c
21 changed files with 201 additions and 119 deletions
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24
mysql-test/main/subselect_no_exists_to_in.result
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@@ -997,9 +997,9 @@ a t1.a in (select t2.a from t2)
explain extended SELECT t1.a, t1.a in (select t2.a from t2) FROM t1;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t1 index NULL PRIMARY 4 NULL 4 100.00 Using index
2 SUBQUERY t2 index_subquery a a 5 func 2 100.00 Using index
2 DEPENDENT SUBQUERY t2 index_subquery a a 5 func 2 100.00 Using index; Using where
Warnings:
Note 1003 /* select#1 */ select `test`.`t1`.`a` AS `a`,<expr_cache><`test`.`t1`.`a`>(<in_optimizer>(`test`.`t1`.`a`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`a`) in t2 on a checking NULL having `test`.`t2`.`a` is null)))) AS `t1.a in (select t2.a from t2)` from `test`.`t1`
Note 1003 /* select#1 */ select `test`.`t1`.`a` AS `a`,<expr_cache><`test`.`t1`.`a`>(<in_optimizer>(`test`.`t1`.`a`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`a`) in t2 on a checking NULL where <cache>(`test`.`t1`.`a`) = `test`.`t2`.`a` or `test`.`t2`.`a` is null having `test`.`t2`.`a` is null)))) AS `t1.a in (select t2.a from t2)` from `test`.`t1`
CREATE TABLE t3 (a int(11) default '0');
INSERT INTO t3 VALUES (1),(2),(3);
SELECT t1.a, t1.a in (select t2.a from t2,t3 where t3.a=t2.a) FROM t1;
@@ -1706,27 +1706,27 @@ a3 1
explain extended select s1, s1 NOT IN (SELECT s1 FROM t2) from t1;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t1 index NULL s1 6 NULL 3 100.00 Using index
2 SUBQUERY t2 index_subquery s1 s1 6 func 2 100.00 Using index; Full scan on NULL key
2 DEPENDENT SUBQUERY t2 index_subquery s1 s1 6 func 2 100.00 Using index; Using where; Full scan on NULL key
Warnings:
Note 1003 /* select#1 */ select `test`.`t1`.`s1` AS `s1`,!<expr_cache><`test`.`t1`.`s1`>(<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL having trigcond(`test`.`t2`.`s1` is null))))) AS `s1 NOT IN (SELECT s1 FROM t2)` from `test`.`t1`
Note 1003 /* select#1 */ select `test`.`t1`.`s1` AS `s1`,!<expr_cache><`test`.`t1`.`s1`>(<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL where trigcond(<cache>(`test`.`t1`.`s1`) = `test`.`t2`.`s1` or `test`.`t2`.`s1` is null) having trigcond(`test`.`t2`.`s1` is null))))) AS `s1 NOT IN (SELECT s1 FROM t2)` from `test`.`t1`
explain extended select s1, s1 = ANY (SELECT s1 FROM t2) from t1;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t1 index NULL s1 6 NULL 3 100.00 Using index
2 SUBQUERY t2 index_subquery s1 s1 6 func 2 100.00 Using index; Full scan on NULL key
2 DEPENDENT SUBQUERY t2 index_subquery s1 s1 6 func 2 100.00 Using index; Using where; Full scan on NULL key
Warnings:
Note 1003 /* select#1 */ select `test`.`t1`.`s1` AS `s1`,<expr_cache><`test`.`t1`.`s1`>(<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL having trigcond(`test`.`t2`.`s1` is null))))) AS `s1 = ANY (SELECT s1 FROM t2)` from `test`.`t1`
Note 1003 /* select#1 */ select `test`.`t1`.`s1` AS `s1`,<expr_cache><`test`.`t1`.`s1`>(<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL where trigcond(<cache>(`test`.`t1`.`s1`) = `test`.`t2`.`s1` or `test`.`t2`.`s1` is null) having trigcond(`test`.`t2`.`s1` is null))))) AS `s1 = ANY (SELECT s1 FROM t2)` from `test`.`t1`
explain extended select s1, s1 <> ALL (SELECT s1 FROM t2) from t1;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t1 index NULL s1 6 NULL 3 100.00 Using index
2 SUBQUERY t2 index_subquery s1 s1 6 func 2 100.00 Using index; Full scan on NULL key
2 DEPENDENT SUBQUERY t2 index_subquery s1 s1 6 func 2 100.00 Using index; Using where; Full scan on NULL key
Warnings:
Note 1003 /* select#1 */ select `test`.`t1`.`s1` AS `s1`,!<expr_cache><`test`.`t1`.`s1`>(<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL having trigcond(`test`.`t2`.`s1` is null))))) AS `s1 <> ALL (SELECT s1 FROM t2)` from `test`.`t1`
Note 1003 /* select#1 */ select `test`.`t1`.`s1` AS `s1`,!<expr_cache><`test`.`t1`.`s1`>(<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL where trigcond(<cache>(`test`.`t1`.`s1`) = `test`.`t2`.`s1` or `test`.`t2`.`s1` is null) having trigcond(`test`.`t2`.`s1` is null))))) AS `s1 <> ALL (SELECT s1 FROM t2)` from `test`.`t1`
explain extended select s1, s1 NOT IN (SELECT s1 FROM t2 WHERE s1 < 'a2') from t1;
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t1 index NULL s1 6 NULL 3 100.00 Using index
2 SUBQUERY t2 index_subquery s1 s1 6 func 2 50.00 Using index; Using where; Full scan on NULL key
2 DEPENDENT SUBQUERY t2 index_subquery s1 s1 6 func 2 50.00 Using index; Using where; Full scan on NULL key
Warnings:
Note 1003 /* select#1 */ select `test`.`t1`.`s1` AS `s1`,!<expr_cache><`test`.`t1`.`s1`>(<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL where `test`.`t2`.`s1` < 'a2' having trigcond(`test`.`t2`.`s1` is null))))) AS `s1 NOT IN (SELECT s1 FROM t2 WHERE s1 < 'a2')` from `test`.`t1`
Note 1003 /* select#1 */ select `test`.`t1`.`s1` AS `s1`,!<expr_cache><`test`.`t1`.`s1`>(<in_optimizer>(`test`.`t1`.`s1`,<exists>(<index_lookup>(<cache>(`test`.`t1`.`s1`) in t2 on s1 checking NULL where `test`.`t2`.`s1` < 'a2' and trigcond(<cache>(`test`.`t1`.`s1`) = `test`.`t2`.`s1` or `test`.`t2`.`s1` is null) having trigcond(`test`.`t2`.`s1` is null))))) AS `s1 NOT IN (SELECT s1 FROM t2 WHERE s1 < 'a2')` from `test`.`t1`
drop table t1,t2;
create table t2 (a int, b int not null);
create table t3 (a int);
@@ -3277,7 +3277,7 @@ INSERT INTO t2 VALUES (1),(2),(3);
EXPLAIN SELECT a, a IN (SELECT a FROM t1) FROM t2;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 ALL NULL NULL NULL NULL 3
2 SUBQUERY t1 index_subquery a a 5 func 3 Using index; Full scan on NULL key
2 DEPENDENT SUBQUERY t1 index_subquery a a 5 func 3 Using index; Using where; Full scan on NULL key
SELECT a, a IN (SELECT a FROM t1) FROM t2;
a a IN (SELECT a FROM t1)
1 1
@@ -6762,7 +6762,7 @@ SET @@optimizer_switch='semijoin=off,materialization=off,in_to_exists=on,subquer
EXPLAIN SELECT * FROM t1 WHERE a IN (SELECT a AS field1 FROM t1 GROUP BY field1);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t1 index NULL a 4 NULL 2 Using where; Using index
2 DEPENDENT SUBQUERY t1 index_subquery a a 4 func 1 Using index
2 SUBQUERY t1 index_subquery a a 4 func 1 Using index
SELECT * FROM t1 WHERE a IN (SELECT a AS field1 FROM t1 GROUP BY field1);
a
2009-01-01