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Fixed LP bug #702301.

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The function matching_cond should take into account that
there may be always false constant conjunctive conditions
that has not been evaluated yet,for example, conjunctive
conditions with non-correlated subqueries.
This commit is contained in:
Igor Babaev
2011-07-20 16:09:28 -07:00
parent 36be492dc0
commit 57f4965f36
5 changed files with 73 additions and 11 deletions
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4
mysql-test/r/myisam_mrr.result
View File

@ -349,10 +349,10 @@ WHERE t2.int_key IS NULL
GROUP BY t2.pk
);
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY NULL NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
1 PRIMARY t1 system NULL NULL NULL NULL 1 100.00
2 SUBQUERY t2 ref int_key int_key 5 const 1 100.00 Using index condition; Using where; Using filesort
Warnings:
Note 1003 select min(`test`.`t1`.`pk`) AS `MIN(t1.pk)` from `test`.`t1` where exists(select `test`.`t2`.`pk` from `test`.`t2` where isnull(`test`.`t2`.`int_key`) group by `test`.`t2`.`pk`)
Note 1003 select min(1) AS `MIN(t1.pk)` from `test`.`t1` where exists(select `test`.`t2`.`pk` from `test`.`t2` where isnull(`test`.`t2`.`int_key`) group by `test`.`t2`.`pk`)
DROP TABLE t1, t2;
#
# BUG#42048 Discrepancy between MyISAM and Maria's ICP implementation

45
mysql-test/r/subselect_mat.result
View File

@ -1150,43 +1150,48 @@ create table t2 (b1 int);
insert into t1 values (5);
explain select min(a1) from t1 where 7 in (select b1 from t2 group by b1);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
1 PRIMARY t1 system NULL NULL NULL NULL 1
2 SUBQUERY t2 system NULL NULL NULL NULL 0 const row not found
select min(a1) from t1 where 7 in (select b1 from t2 group by b1);
min(a1)
NULL
set @save_optimizer_switch=@@optimizer_switch;
set @@optimizer_switch=@optimizer_switch_local_default;
set @@optimizer_switch='materialization=off,in_to_exists=on';
explain select min(a1) from t1 where 7 in (select b1 from t2 group by b1);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
1 PRIMARY t1 system NULL NULL NULL NULL 1
2 DEPENDENT SUBQUERY t2 system NULL NULL NULL NULL 0 const row not found
select min(a1) from t1 where 7 in (select b1 from t2 group by b1);
min(a1)
NULL
set @@optimizer_switch=@optimizer_switch_local_default;
set @@optimizer_switch='semijoin=off';
explain select min(a1) from t1 where 7 in (select b1 from t2);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
1 PRIMARY t1 system NULL NULL NULL NULL 1
2 SUBQUERY t2 system NULL NULL NULL NULL 0 const row not found
select min(a1) from t1 where 7 in (select b1 from t2);
min(a1)
NULL
set @@optimizer_switch=@optimizer_switch_local_default;
set @@optimizer_switch='materialization=off,in_to_exists=on';
# with MariaDB and MWL#90, this particular case is solved:
explain select min(a1) from t1 where 7 in (select b1 from t2);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
1 PRIMARY t1 system NULL NULL NULL NULL 1
2 DEPENDENT SUBQUERY NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables
select min(a1) from t1 where 7 in (select b1 from t2);
min(a1)
NULL
# but when we go around MWL#90 code, the problem still shows up:
explain select min(a1) from t1 where 7 in (select b1 from t2) or 2> 4;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
1 PRIMARY t1 system NULL NULL NULL NULL 1
2 DEPENDENT SUBQUERY NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables
select min(a1) from t1 where 7 in (select b1 from t2) or 2> 4;
min(a1)
NULL
set @@optimizer_switch= @save_optimizer_switch;
drop table t1,t2;
create table t1 (a char(2), b varchar(10));
@ -1555,3 +1560,33 @@ FROM t2;
(SELECT COUNT(DISTINCT f2), f1, f3 FROM t1 GROUP BY f1, f3)
1
drop table t1, t2;
#
# LPBUG#702301: MAX in select + always false WHERE with SQ
#
CREATE TABLE t1 (a int, b int, KEY (b));
INSERT INTO t1 VALUES (3,1), (4,2);
CREATE TABLE t2 (a int);
INSERT INTO t2 VALUES (7), (8);
set @@optimizer_switch='materialization=on,in_to_exists=off,semijoin=off';
SELECT MAX(t1.b) AS max_res FROM t1 WHERE (9) IN (SELECT a FROM t2);
max_res
NULL
EXPLAIN EXTENDED
SELECT MAX(t1.b) AS max_res FROM t1 WHERE (9) IN (SELECT a FROM t2);
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t1 index NULL b 5 NULL 2 100.00 Using index
2 SUBQUERY t2 ALL NULL NULL NULL NULL 2 100.00
Warnings:
Note 1003 select max(`test`.`t1`.`b`) AS `max_res` from `test`.`t1` where <in_optimizer>(9,9 in ( <materialize> (select `test`.`t2`.`a` from `test`.`t2` ), <primary_index_lookup>(9 in <temporary table> on distinct_key where ((9 = `<subquery2>`.`a`)))))
set @@optimizer_switch='materialization=off,in_to_exists=on,semijoin=off';
SELECT MAX(t1.b) AS max_res FROM t1 WHERE (9) IN (SELECT a FROM t2);
max_res
NULL
EXPLAIN EXTENDED
SELECT MAX(t1.b) AS max_res FROM t1 WHERE (9) IN (SELECT a FROM t2);
id select_type table type possible_keys key key_len ref rows filtered Extra
1 PRIMARY t1 index NULL b 5 NULL 2 100.00 Using index
2 DEPENDENT SUBQUERY t2 ALL NULL NULL NULL NULL 2 100.00 Using where
Warnings:
Note 1003 select max(`test`.`t1`.`b`) AS `max_res` from `test`.`t1` where <in_optimizer>(9,<exists>(select `test`.`t2`.`a` from `test`.`t2` where (9 = `test`.`t2`.`a`)))
DROP TABLE t1,t2;

9
mysql-test/r/subselect_sj_mat.result
View File

@ -1196,18 +1196,20 @@ set @@optimizer_switch=@optimizer_switch_local_default;
set @@optimizer_switch='materialization=off,in_to_exists=on';
explain select min(a1) from t1 where 7 in (select b1 from t2 group by b1);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
1 PRIMARY t1 system NULL NULL NULL NULL 1
2 DEPENDENT SUBQUERY t2 system NULL NULL NULL NULL 0 const row not found
select min(a1) from t1 where 7 in (select b1 from t2 group by b1);
min(a1)
NULL
set @@optimizer_switch=@optimizer_switch_local_default;
set @@optimizer_switch='semijoin=off';
explain select min(a1) from t1 where 7 in (select b1 from t2);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
1 PRIMARY t1 system NULL NULL NULL NULL 1
2 DEPENDENT SUBQUERY NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables
select min(a1) from t1 where 7 in (select b1 from t2);
min(a1)
NULL
set @@optimizer_switch=@optimizer_switch_local_default;
set @@optimizer_switch='materialization=off,in_to_exists=on';
# with MariaDB and MWL#90, this particular case is solved:
@ -1220,10 +1222,11 @@ NULL
# but when we go around MWL#90 code, the problem still shows up:
explain select min(a1) from t1 where 7 in (select b1 from t2) or 2> 4;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
1 PRIMARY t1 system NULL NULL NULL NULL 1
2 DEPENDENT SUBQUERY NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables
select min(a1) from t1 where 7 in (select b1 from t2) or 2> 4;
min(a1)
NULL
set @@optimizer_switch= @save_optimizer_switch;
drop table t1,t2;
create table t1 (a char(2), b varchar(10));

24
mysql-test/t/subselect_mat.test
View File

@ -202,3 +202,27 @@ SELECT (f1, f2, f3) NOT IN
FROM t2;
drop table t1, t2;
--echo #
--echo # LPBUG#702301: MAX in select + always false WHERE with SQ
--echo #
CREATE TABLE t1 (a int, b int, KEY (b));
INSERT INTO t1 VALUES (3,1), (4,2);
CREATE TABLE t2 (a int);
INSERT INTO t2 VALUES (7), (8);
set @@optimizer_switch='materialization=on,in_to_exists=off,semijoin=off';
SELECT MAX(t1.b) AS max_res FROM t1 WHERE (9) IN (SELECT a FROM t2);
EXPLAIN EXTENDED
SELECT MAX(t1.b) AS max_res FROM t1 WHERE (9) IN (SELECT a FROM t2);
set @@optimizer_switch='materialization=off,in_to_exists=on,semijoin=off';
SELECT MAX(t1.b) AS max_res FROM t1 WHERE (9) IN (SELECT a FROM t2);
EXPLAIN EXTENDED
SELECT MAX(t1.b) AS max_res FROM t1 WHERE (9) IN (SELECT a FROM t2);
DROP TABLE t1,t2;

2
sql/opt_sum.cc
View File

@ -623,7 +623,7 @@ static bool matching_cond(bool max_fl, TABLE_REF *ref, KEY *keyinfo,
if (!(cond->used_tables() & field->table->map))
{
/* Condition doesn't restrict the used table */
DBUG_RETURN(TRUE);
DBUG_RETURN(!cond->const_item());
}
if (cond->type() == Item::COND_ITEM)
{