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Merge fix for BUG#922254

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This commit is contained in:
Sergey Petrunya 2012-01-30 17:38:14 +04:00
commit 9fce78a482
4 changed files with 63 additions and 4 deletions
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20
mysql-test/r/subselect_mat.result
View file

@ -1811,6 +1811,26 @@ a b c
4 4 2
4 4 4
DROP TABLE t1,t2;
#
# BUG#922254: Assertion `0' failed at item_cmpfunc.cc:5899: Item* Item_equal::get_first(JOIN_TAB*, Item*)
#
CREATE TABLE t1 ( a VARCHAR(3) );
CREATE TABLE t2 ( b VARCHAR(3), c VARCHAR(8), KEY(c) );
INSERT INTO t2 VALUES ('USA','Abilene'),('USA','Akron');
EXPLAIN
SELECT * FROM
( SELECT * FROM t1 ) AS alias1,
t2 AS alias2
WHERE b = a AND a IN (
SELECT alias3.c
FROM t2 AS alias3, t2 AS alias4
WHERE alias4.c = alias3.b
);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables
3 MATERIALIZED alias3 ALL NULL NULL NULL NULL 2
3 MATERIALIZED alias4 index c c 11 NULL 2 Using where; Using index; Using join buffer (flat, BNL join)
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;

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

@ -1849,6 +1849,24 @@ a b c
4 4 2
4 4 4
DROP TABLE t1,t2;
#
# BUG#922254: Assertion `0' failed at item_cmpfunc.cc:5899: Item* Item_equal::get_first(JOIN_TAB*, Item*)
#
CREATE TABLE t1 ( a VARCHAR(3) );
CREATE TABLE t2 ( b VARCHAR(3), c VARCHAR(8), KEY(c) );
INSERT INTO t2 VALUES ('USA','Abilene'),('USA','Akron');
EXPLAIN
SELECT * FROM
( SELECT * FROM t1 ) AS alias1,
t2 AS alias2
WHERE b = a AND a IN (
SELECT alias3.c
FROM t2 AS alias3, t2 AS alias4
WHERE alias4.c = alias3.b
);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY NULL NULL NULL NULL NULL NULL NULL Impossible WHERE noticed after reading const tables
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;

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

@ -1510,6 +1510,25 @@ SELECT * FROM t1 LEFT JOIN t2 ON ( a = b )
DROP TABLE t1,t2;
--echo #
--echo # BUG#922254: Assertion `0' failed at item_cmpfunc.cc:5899: Item* Item_equal::get_first(JOIN_TAB*, Item*)
--echo #
CREATE TABLE t1 ( a VARCHAR(3) );
CREATE TABLE t2 ( b VARCHAR(3), c VARCHAR(8), KEY(c) );
INSERT INTO t2 VALUES ('USA','Abilene'),('USA','Akron');
EXPLAIN
SELECT * FROM
( SELECT * FROM t1 ) AS alias1,
t2 AS alias2
WHERE b = a AND a IN (
SELECT alias3.c
FROM t2 AS alias3, t2 AS alias4
WHERE alias4.c = alias3.b
);
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;

10
sql/item_cmpfunc.cc
View file

@ -5853,13 +5853,15 @@ Item* Item_equal::get_first(JOIN_TAB *context, Item *field_item)
if (emb_nest && emb_nest->sj_mat_info && emb_nest->sj_mat_info->is_used)
{
/*
It's a field from an materialized semi-join. We can substitute it only
for a field from the same semi-join. Find the first of such items.
It's a field from an materialized semi-join. We can substitute it for
- a constant item
- a field from the same semi-join
Find the first of such items:
*/
while ((item= it++))
{
if (it.get_curr_field()->table->pos_in_table_list->embedding == emb_nest)
if (item->const_item() ||
it.get_curr_field()->table->pos_in_table_list->embedding == emb_nest)
{
/*
If we found given field then return NULL to avoid unnecessary