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BUG#978479: Wrong result (extra rows) with derived_with_keys+loosescan+semijoin=ON, materialization=OFF

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Part#1: make EXPLAIN's plan match the one by actual execution: 
Item_subselect::used_tables() should return the same value irrespectively 
of whether we're running an EXPLAIN or a SELECT.
This commit is contained in:
Sergey Petrunya 2012-04-19 04:50:32 +04:00
parent 2004bd1736
commit 994c6db2d1
4 changed files with 86 additions and 1 deletions
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27
mysql-test/r/subselect_sj.result
View file

@ -2661,4 +2661,31 @@ a
DEALLOCATE PREPARE pstmt;
DROP VIEW v1;
DROP TABLE t1, t2;
#
# BUG#978479: Wrong result (extra rows) with derived_with_keys+loosescan+semijoin=ON, materialization=OFF
#
set @tmp_jcl_978479= @@join_cache_level;
set join_cache_level=0;
set @tmp_os_978479= @@optimizer_switch;
set optimizer_switch = 'derived_with_keys=on,loosescan=on,semijoin=on,materialization=off';
# Part#1: make sure EXPLAIN is using LooseScan:
CREATE TABLE t1 ( a INT, b INT );
INSERT INTO t1 VALUES
(4,0),(6,8),(3,1),(5,8),(3,9),(2,4),
(2,6),(9,1),(5,4),(7,7),(5,4);
CREATE ALGORITHM=TEMPTABLE
VIEW v1 AS SELECT * FROM t1;
# This will use LooseScan:
EXPLAIN
SELECT * FROM t1 AS t1_1, t1 AS t1_2
WHERE (t1_1.a, t1_2.a) IN ( SELECT a, b FROM v1 );
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t1_1 ALL NULL NULL NULL NULL 11
1 PRIMARY <derived3> ALL NULL NULL NULL NULL 11 Using where; LooseScan
1 PRIMARY t1_2 ALL NULL NULL NULL NULL 11 Using where
3 DERIVED t1 ALL NULL NULL NULL NULL 11
DROP VIEW v1;
DROP TABLE t1;
set @@join_cache_level= @tmp_jcl_978479;
set @@optimizer_switch= @tmp_os_978479;
set optimizer_switch=@subselect_sj_tmp;

27
mysql-test/r/subselect_sj_jcl6.result
View file

@ -2675,6 +2675,33 @@ a
DEALLOCATE PREPARE pstmt;
DROP VIEW v1;
DROP TABLE t1, t2;
#
# BUG#978479: Wrong result (extra rows) with derived_with_keys+loosescan+semijoin=ON, materialization=OFF
#
set @tmp_jcl_978479= @@join_cache_level;
set join_cache_level=0;
set @tmp_os_978479= @@optimizer_switch;
set optimizer_switch = 'derived_with_keys=on,loosescan=on,semijoin=on,materialization=off';
# Part#1: make sure EXPLAIN is using LooseScan:
CREATE TABLE t1 ( a INT, b INT );
INSERT INTO t1 VALUES
(4,0),(6,8),(3,1),(5,8),(3,9),(2,4),
(2,6),(9,1),(5,4),(7,7),(5,4);
CREATE ALGORITHM=TEMPTABLE
VIEW v1 AS SELECT * FROM t1;
# This will use LooseScan:
EXPLAIN
SELECT * FROM t1 AS t1_1, t1 AS t1_2
WHERE (t1_1.a, t1_2.a) IN ( SELECT a, b FROM v1 );
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t1_1 ALL NULL NULL NULL NULL 11
1 PRIMARY <derived3> ALL NULL NULL NULL NULL 11 Using where; LooseScan
1 PRIMARY t1_2 ALL NULL NULL NULL NULL 11 Using where
3 DERIVED t1 ALL NULL NULL NULL NULL 11
DROP VIEW v1;
DROP TABLE t1;
set @@join_cache_level= @tmp_jcl_978479;
set @@optimizer_switch= @tmp_os_978479;
set optimizer_switch=@subselect_sj_tmp;
#
# BUG#49129: Wrong result with IN-subquery with join_cache_level=6 and firstmatch=off

30
mysql-test/t/subselect_sj.test
View file

@ -2366,5 +2366,35 @@ DEALLOCATE PREPARE pstmt;
DROP VIEW v1;
DROP TABLE t1, t2;
--echo #
--echo # BUG#978479: Wrong result (extra rows) with derived_with_keys+loosescan+semijoin=ON, materialization=OFF
--echo #
set @tmp_jcl_978479= @@join_cache_level;
set join_cache_level=0;
set @tmp_os_978479= @@optimizer_switch;
set optimizer_switch = 'derived_with_keys=on,loosescan=on,semijoin=on,materialization=off';
--echo # Part#1: make sure EXPLAIN is using LooseScan:
CREATE TABLE t1 ( a INT, b INT );
INSERT INTO t1 VALUES
(4,0),(6,8),(3,1),(5,8),(3,9),(2,4),
(2,6),(9,1),(5,4),(7,7),(5,4);
CREATE ALGORITHM=TEMPTABLE
VIEW v1 AS SELECT * FROM t1;
--echo # This will use LooseScan:
EXPLAIN
SELECT * FROM t1 AS t1_1, t1 AS t1_2
WHERE (t1_1.a, t1_2.a) IN ( SELECT a, b FROM v1 );
DROP VIEW v1;
DROP TABLE t1;
set @@join_cache_level= @tmp_jcl_978479;
set @@optimizer_switch= @tmp_os_978479;
# The following command must be the last one the file
set optimizer_switch=@subselect_sj_tmp;

3
sql/item_subselect.cc
View file

@ -757,7 +757,8 @@ void Item_subselect::fix_length_and_dec()
table_map Item_subselect::used_tables() const
{
return (table_map) (engine->uncacheable() ? used_tables_cache : 0L);
return (table_map) ((engine->uncacheable() & ~UNCACHEABLE_EXPLAIN)?
used_tables_cache : 0L);
}