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BUG#860300: Second crash with get_fanout_with_deps() with semijoin + materialization

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- Make get_post_group_estimate() take into account semi-join materialization nests.
This commit is contained in:
Sergey Petrunya 2011-09-28 12:58:01 +04:00
commit 35ecfa90e3
4 changed files with 62 additions and 1 deletions
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18
mysql-test/r/subselect_mat.result
View file

@ -1657,6 +1657,24 @@ a
0
DROP TABLE t2,t3,t4,t5;
set optimizer_switch=@subselect_sj_mat_tmp;
#
# BUG#860300: Second crash with get_fanout_with_deps() with semijoin + materialization
#
set @tmp_860300=@@optimizer_switch;
set optimizer_switch='semijoin=on,materialization=on,loosescan=off,firstmatch=off';
CREATE TABLE t1 (f2 int);
INSERT INTO t1 VALUES (9),(6);
CREATE TABLE t3 (f4 int);
CREATE TABLE t4 (f6 varchar(1));
SELECT *
FROM t3
WHERE 'h' IN (SELECT f6
FROM t4
WHERE 5 IN (SELECT f2 FROM t1)
GROUP BY t4.f6);
f4
DROP TABLE t1,t3,t4;
set optimizer_switch=@tmp_860300;
set @subselect_mat_test_optimizer_switch_value=null;
set @@optimizer_switch='materialization=on,in_to_exists=off,semijoin=off';
set optimizer_switch='mrr=on,mrr_sort_keys=on,index_condition_pushdown=on';

18
mysql-test/r/subselect_sj_mat.result
View file

@ -1697,3 +1697,21 @@ a
0
DROP TABLE t2,t3,t4,t5;
set optimizer_switch=@subselect_sj_mat_tmp;
#
# BUG#860300: Second crash with get_fanout_with_deps() with semijoin + materialization
#
set @tmp_860300=@@optimizer_switch;
set optimizer_switch='semijoin=on,materialization=on,loosescan=off,firstmatch=off';
CREATE TABLE t1 (f2 int);
INSERT INTO t1 VALUES (9),(6);
CREATE TABLE t3 (f4 int);
CREATE TABLE t4 (f6 varchar(1));
SELECT *
FROM t3
WHERE 'h' IN (SELECT f6
FROM t4
WHERE 5 IN (SELECT f2 FROM t1)
GROUP BY t4.f6);
f4
DROP TABLE t1,t3,t4;
set optimizer_switch=@tmp_860300;

19
mysql-test/t/subselect_sj_mat.test
View file

@ -1351,3 +1351,22 @@ DROP TABLE t2,t3,t4,t5;
set optimizer_switch=@subselect_sj_mat_tmp;
--echo #
--echo # BUG#860300: Second crash with get_fanout_with_deps() with semijoin + materialization
--echo #
set @tmp_860300=@@optimizer_switch;
set optimizer_switch='semijoin=on,materialization=on,loosescan=off,firstmatch=off';
CREATE TABLE t1 (f2 int);
INSERT INTO t1 VALUES (9),(6);
CREATE TABLE t3 (f4 int);
CREATE TABLE t4 (f6 varchar(1));
SELECT *
FROM t3
WHERE 'h' IN (SELECT f6
FROM t4
WHERE 5 IN (SELECT f2 FROM t1)
GROUP BY t4.f6);
DROP TABLE t1,t3,t4;
set optimizer_switch=@tmp_860300;

8
sql/item_subselect.cc
View file

@ -4394,7 +4394,13 @@ double get_fanout_with_deps(JOIN *join, table_map tset)
for (JOIN_TAB *tab= first_top_level_tab(join, WITHOUT_CONST_TABLES); tab;
tab= next_top_level_tab(join, tab))
{
if ((tab->table->map & checked_deps) && !tab->emb_sj_nest &&
/*
Ignore SJM nests. They have tab->table==NULL. There is no point to walk
inside them, because GROUP BY clause cannot refer to tables from within
subquery.
*/
if (!tab->is_sjm_nest() && (tab->table->map & checked_deps) &&
!tab->emb_sj_nest &&
tab->records_read != 0)
{
fanout *= rows2double(tab->records_read);