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Fixed LP bug #899509.

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The optimizer must ignore any possible hash join key when looking for the 
query execution plan with join_cache_level set to 0.
This commit is contained in:
Igor Babaev
2011-12-06 02:46:42 -08:00
parent 62e4c73ebb
commit b4c9fa321d
6 changed files with 75 additions and 6 deletions
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4
mysql-test/r/derived.result
View File

@ -192,13 +192,13 @@ pla_id test
explain SELECT STRAIGHT_JOIN d.pla_id, m2.mat_id FROM t1 m2 INNER JOIN (SELECT mp.pla_id, MIN(m1.matintnum) AS matintnum FROM t2 mp INNER JOIN t1 m1 ON mp.mat_id=m1.mat_id GROUP BY mp.pla_id) d ON d.matintnum=m2.matintnum;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY m2 ALL NULL NULL NULL NULL 9
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 9 Using where
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 9 Using where; Using join buffer (flat, BNL join)
2 DERIVED mp ALL NULL NULL NULL NULL 9 Using temporary; Using filesort
2 DERIVED m1 eq_ref PRIMARY PRIMARY 3 test.mp.mat_id 1
explain SELECT STRAIGHT_JOIN d.pla_id, m2.test FROM t1 m2 INNER JOIN (SELECT mp.pla_id, MIN(m1.matintnum) AS matintnum FROM t2 mp INNER JOIN t1 m1 ON mp.mat_id=m1.mat_id GROUP BY mp.pla_id) d ON d.matintnum=m2.matintnum;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY m2 ALL NULL NULL NULL NULL 9
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 9 Using where
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 9 Using where; Using join buffer (flat, BNL join)
2 DERIVED mp ALL NULL NULL NULL NULL 9 Using temporary; Using filesort
2 DERIVED m1 eq_ref PRIMARY PRIMARY 3 test.mp.mat_id 1
drop table t1,t2;

38
mysql-test/r/join_cache.result
View File

@ -5226,4 +5226,42 @@ a b c
SET SESSION join_cache_level = DEFAULT;
SET optimizer_switch=@tmp_optimizer_switch;
DROP TABLE t1,t2,t3,t4;
#
# Bug #899509: an attempt to use hash join with join_cache_level=0
#
CREATE TABLE t1 (a int);
INSERT INTO t1 VALUES (8), (7);
CREATE TABLE t2 (a int);
INSERT INTO t2 VALUES (8), (7);
CREATE TABLE t3 (a int);
INSERT INTO t3 VALUES (8), (7);
SET @tmp_optimizer_switch=@@optimizer_switch;
set optimizer_switch=default;
set @@optimizer_switch='semijoin_with_cache=off';
set @@optimizer_switch='outer_join_with_cache=off';
SET optimizer_switch='derived_merge=off,derived_with_keys=off';
SET join_cache_level=0;
EXPLAIN
SELECT * FROM (SELECT t1.* FROM t1, t2) t WHERE t.a IN (SELECT * FROM t3);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <subquery3> ALL distinct_key NULL NULL NULL 2
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 4 Using where
3 MATERIALIZED t3 ALL NULL NULL NULL NULL 2
2 DERIVED t1 ALL NULL NULL NULL NULL 2
2 DERIVED t2 ALL NULL NULL NULL NULL 2
SELECT * FROM (SELECT t1.* FROM t1, t2) t WHERE t.a IN (SELECT * FROM t3);
a
8
8
7
7
SELECT * FROM ( SELECT ta.* FROM t1 AS ta, t1 ) tb WHERE a IN ( SELECT * FROM t1 );
a
8
8
7
7
SET SESSION join_cache_level = DEFAULT;
SET optimizer_switch=@tmp_optimizer_switch;
DROP TABLE t1,t2,t3;
set @@optimizer_switch=@save_optimizer_switch;

2
mysql-test/r/subselect_extra.result
View File

@ -432,7 +432,7 @@ WHERE t2.c = v1.c AND t2.c = v1.b AND v1.b = t3.c);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 system NULL NULL NULL NULL 1
1 PRIMARY t3 ALL NULL NULL NULL NULL 2 Using where
1 PRIMARY <derived3> ALL NULL NULL NULL NULL 3 Using where; Start temporary; End temporary
1 PRIMARY <derived3> ALL NULL NULL NULL NULL 3 Using where; Start temporary; End temporary; Using join buffer (flat, BNL join)
3 DERIVED t1 ALL NULL NULL NULL NULL 3
SELECT * FROM t3
WHERE t3.b IN (SELECT v1.b FROM v1, t2

4
mysql-test/suite/pbxt/r/derived.result
View File

@ -192,13 +192,13 @@ pla_id test
explain SELECT STRAIGHT_JOIN d.pla_id, m2.mat_id FROM t1 m2 INNER JOIN (SELECT mp.pla_id, MIN(m1.matintnum) AS matintnum FROM t2 mp INNER JOIN t1 m1 ON mp.mat_id=m1.mat_id GROUP BY mp.pla_id) d ON d.matintnum=m2.matintnum;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY m2 ALL NULL NULL NULL NULL 9
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 9 Using where
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 9 Using where; Using join buffer (flat, BNL join)
2 DERIVED mp ALL NULL NULL NULL NULL 9 Using temporary; Using filesort
2 DERIVED m1 eq_ref PRIMARY PRIMARY 3 test.mp.mat_id 1
explain SELECT STRAIGHT_JOIN d.pla_id, m2.test FROM t1 m2 INNER JOIN (SELECT mp.pla_id, MIN(m1.matintnum) AS matintnum FROM t2 mp INNER JOIN t1 m1 ON mp.mat_id=m1.mat_id GROUP BY mp.pla_id) d ON d.matintnum=m2.matintnum;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY m2 ALL NULL NULL NULL NULL 9
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 9 Using where
1 PRIMARY <derived2> ALL NULL NULL NULL NULL 9 Using where; Using join buffer (flat, BNL join)
2 DERIVED mp ALL NULL NULL NULL NULL 9 Using temporary; Using filesort
2 DERIVED m1 eq_ref PRIMARY PRIMARY 3 test.mp.mat_id 1
drop table t1,t2;

29
mysql-test/t/join_cache.test
View File

@ -3294,5 +3294,34 @@ SET optimizer_switch=@tmp_optimizer_switch;
DROP TABLE t1,t2,t3,t4;
--echo #
--echo # Bug #899509: an attempt to use hash join with join_cache_level=0
--echo #
CREATE TABLE t1 (a int);
INSERT INTO t1 VALUES (8), (7);
CREATE TABLE t2 (a int);
INSERT INTO t2 VALUES (8), (7);
CREATE TABLE t3 (a int);
INSERT INTO t3 VALUES (8), (7);
SET @tmp_optimizer_switch=@@optimizer_switch;
set optimizer_switch=default;
set @@optimizer_switch='semijoin_with_cache=off';
set @@optimizer_switch='outer_join_with_cache=off';
SET optimizer_switch='derived_merge=off,derived_with_keys=off';
SET join_cache_level=0;
EXPLAIN
SELECT * FROM (SELECT t1.* FROM t1, t2) t WHERE t.a IN (SELECT * FROM t3);
SELECT * FROM (SELECT t1.* FROM t1, t2) t WHERE t.a IN (SELECT * FROM t3);
SELECT * FROM ( SELECT ta.* FROM t1 AS ta, t1 ) tb WHERE a IN ( SELECT * FROM t1 );
SET SESSION join_cache_level = DEFAULT;
SET optimizer_switch=@tmp_optimizer_switch;
DROP TABLE t1,t2,t3;
# this must be the last command in the file
set @@optimizer_switch=@save_optimizer_switch;

2
sql/sql_select.cc
View File

@ -5382,6 +5382,8 @@ best_access_path(JOIN *join,
(2) s is inner table of outer join -> join cache is allowed for outer joins
*/
if (idx > join->const_tables && best_key == 0 &&
(join->allowed_join_cache_types & JOIN_CACHE_HASHED_BIT) &&
join->max_allowed_join_cache_level > 2 &&
!bitmap_is_clear_all(eq_join_set) && !disable_jbuf &&
(!s->emb_sj_nest ||
join->allowed_semijoin_with_cache) && // (1)