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BUG#904432: Wrong result with LEFT JOIN, constant table, semijoin=ON,materialization=ON

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- Correct handling for SJ-Materialization + outer joins (details in the comments in the code)
This commit is contained in:
Sergey Petrunya
2011-12-19 20:58:55 +04:00
parent 263ee55318
commit be3e52984f
4 changed files with 73 additions and 2 deletions
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14
mysql-test/r/subselect_mat.result
View File

@ -1797,6 +1797,20 @@ id select_type table type possible_keys key key_len ref rows filtered Extra
Warnings:
Note 1003 select 8 AS `a` from `test`.`t1` where <expr_cache><8>(<in_optimizer>(8,<exists>(select min(`test`.`t1`.`a`) from `test`.`t1` having (<cache>(8) = <ref_null_helper>(min(`test`.`t1`.`a`))))))
DROP TABLE t1;
#
# BUG#904432: Wrong result with LEFT JOIN, constant table, semijoin=ON,materialization=ON
#
CREATE TABLE t1 ( a INT ) ENGINE=MyISAM;
INSERT INTO t1 VALUES (4);
CREATE TABLE t2 ( b INT NOT NULL, c INT );
INSERT INTO t2 VALUES (4,2),(4,2),(4,4),(1,1);
SELECT * FROM t1 LEFT JOIN t2 ON ( a = b )
WHERE a IN ( SELECT c FROM t2 );
a b c
4 4 2
4 4 2
4 4 4
DROP TABLE t1,t2;
# This must be at the end:
set optimizer_switch=@subselect_sj_mat_tmp;
set join_cache_level=@save_join_cache_level;

14
mysql-test/r/subselect_sj_mat.result
View File

@ -1834,6 +1834,20 @@ id select_type table type possible_keys key key_len ref rows filtered Extra
Warnings:
Note 1003 select 8 AS `a` from <materialize> (select min(`test`.`t1`.`a`) from `test`.`t1`) join `test`.`t1` where 1
DROP TABLE t1;
#
# BUG#904432: Wrong result with LEFT JOIN, constant table, semijoin=ON,materialization=ON
#
CREATE TABLE t1 ( a INT ) ENGINE=MyISAM;
INSERT INTO t1 VALUES (4);
CREATE TABLE t2 ( b INT NOT NULL, c INT );
INSERT INTO t2 VALUES (4,2),(4,2),(4,4),(1,1);
SELECT * FROM t1 LEFT JOIN t2 ON ( a = b )
WHERE a IN ( SELECT c FROM t2 );
a b c
4 4 2
4 4 2
4 4 4
DROP TABLE t1,t2;
# This must be at the end:
set optimizer_switch=@subselect_sj_mat_tmp;
set join_cache_level=@save_join_cache_level;

13
mysql-test/t/subselect_sj_mat.test
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@ -1497,6 +1497,19 @@ EXPLAIN EXTENDED
DROP TABLE t1;
--echo #
--echo # BUG#904432: Wrong result with LEFT JOIN, constant table, semijoin=ON,materialization=ON
--echo #
CREATE TABLE t1 ( a INT ) ENGINE=MyISAM;
INSERT INTO t1 VALUES (4);
CREATE TABLE t2 ( b INT NOT NULL, c INT );
INSERT INTO t2 VALUES (4,2),(4,2),(4,4),(1,1);
SELECT * FROM t1 LEFT JOIN t2 ON ( a = b )
WHERE a IN ( SELECT c FROM t2 );
DROP TABLE t1,t2;
--echo # This must be at the end:
set optimizer_switch=@subselect_sj_mat_tmp;
set join_cache_level=@save_join_cache_level;

34
sql/sql_select.cc
View File

@ -8343,9 +8343,39 @@ make_join_select(JOIN *join,SQL_SELECT *select,COND *cond)
COND *tmp_cond= make_cond_for_table(thd, on_expr, used_tables2,
current_map, /*(tab - first_tab)*/ -1,
FALSE, FALSE);
if (tab == first_inner_tab && tab->on_precond)
bool is_sjm_lookup_tab= FALSE;
if (tab->bush_children)
{
/*
'tab' is an SJ-Materialization tab, i.e. we have a join order
like this:
ot1 sjm_tab LEFT JOIN ot2 ot3
^ ^
'tab'-+ +--- left join we're adding triggers for
LEFT JOIN's ON expression may not have references to subquery
columns. The subquery was in the WHERE clause, so IN-equality
is in the WHERE clause, also.
However, equality propagation code may have propagated the
IN-equality into ON expression, and we may get things like
subquery_inner_table=const
in the ON expression. We must not check such conditions during
SJM-lookup, because 1) subquery_inner_table has no valid current
row (materialization temp.table has it instead), and 2) they
would be true anyway.
*/
SJ_MATERIALIZATION_INFO *sjm=
tab->bush_children->start->emb_sj_nest->sj_mat_info;
if (sjm->is_used && !sjm->is_sj_scan)
is_sjm_lookup_tab= TRUE;
}
if (tab == first_inner_tab && tab->on_precond && !is_sjm_lookup_tab)
add_cond_and_fix(thd, &tmp_cond, tab->on_precond);
if (tmp_cond)
if (tmp_cond && !is_sjm_lookup_tab)
{
JOIN_TAB *cond_tab= tab < first_inner_tab ? first_inner_tab : tab;
Item **sel_cond_ref= tab < first_inner_tab ?