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Fixed bug #934348.

Browse source 
This bug is the result of an incomplete/inconsistent change introduced into
5.3 code when the cond_equal parameter were added to the function optimize_cond.
The change was made during a merge from 5.2 in October 2010.
The bug could affect only queries with HAVING.
This commit is contained in:
Igor Babaev 2012-02-18 19:11:57 -08:00
commit 3ef46370e9
3 changed files with 83 additions and 3 deletions
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43
mysql-test/r/subselect_sj_jcl6.result
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@ -2833,6 +2833,49 @@ set optimizer_switch=@tmp_optimizer_switch;
set join_cache_level=@tmp_join_cache_level;
DROP TABLE t1,t2,t3;
# End
#
# BUG#934348: GROUP BY with HAVING + semijoin materialization
# + join_cache_level > 2
#
CREATE TABLE t1 (a varchar(1), INDEX idx_a(a));
INSERT INTO t1 VALUES ('c'), ('v'), ('c');
CREATE TABLE t2 (b varchar(1));
INSERT INTO t2 VALUES ('v'), ('c');
set @tmp_otimizer_switch= @@optimizer_switch;
set @tmp_join_cache_level=@@join_cache_level;
set optimizer_switch = 'materialization=on,semijoin=on,join_cache_hashed=on';
set join_cache_level=0;
EXPLAIN
SELECT a FROM t1 t WHERE a IN (SELECT b FROM t1, t2 WHERE b = a)
GROUP BY a HAVING a != 'z';
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <subquery2> ALL distinct_key NULL NULL NULL 2 Using temporary; Using filesort
1 PRIMARY t ref idx_a idx_a 4 test.t2.b 2 Using index
2 MATERIALIZED t2 ALL NULL NULL NULL NULL 2 Using where
2 MATERIALIZED t1 ref idx_a idx_a 4 test.t2.b 2 Using index
SELECT a FROM t1 t WHERE a IN (SELECT b FROM t1, t2 WHERE b = a)
GROUP BY a HAVING a != 'z';
a
c
v
set join_cache_level=6;
EXPLAIN
SELECT a FROM t1 t WHERE a IN (SELECT b FROM t1, t2 WHERE b = a)
GROUP BY a HAVING a != 'z';
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <subquery2> ALL distinct_key NULL NULL NULL 2 Using temporary; Using filesort
1 PRIMARY t ref idx_a idx_a 4 test.t2.b 2 Using index
2 MATERIALIZED t2 ALL NULL NULL NULL NULL 2 Using where
2 MATERIALIZED t1 ref idx_a idx_a 4 test.t2.b 2 Using index
SELECT a FROM t1 t WHERE a IN (SELECT b FROM t1, t2 WHERE b = a)
GROUP BY a HAVING a != 'z';
a
c
v
set optimizer_switch=@tmp_optimizer_switch;
set join_cache_level=@tmp_join_cache_level;
DROP TABLE t1,t2;
# End
set join_cache_level=default;
show variables like 'join_cache_level';
Variable_name Value