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Fix LP BUG#719198

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Analysis:
The assert failed because the execution code for
partial matching is designed with the assumption that
NULLs on the left side are detected as early as possible,
and a NULL result is returned before any lookups are
performed at all.

However, in the case of an Item_cache object on the left
side, null was not detected properly, because detection
was done via Item::is_null(), which is not implemented at
all for Item_cache, and resolved to the default Item::is_null()
which always returns FALSE.

Solution:
Use the property Item::null_value instead of is_null(), which
is properly updated for Item_cache objects as well.
This commit is contained in:
unknown 2011-03-08 23:23:44 +02:00
parent 0d5d68f684
commit 546a166b4e
4 changed files with 74 additions and 1 deletions
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38
mysql-test/r/subselect_mat.result
View File

@ -1371,3 +1371,41 @@ SELECT pk FROM t1 WHERE (b,c,d) IN (SELECT b,c,d FROM t2 WHERE pk > 0);
pk
2
DROP TABLE t1, t2;
#
# LPBUG#719198 Ordered_key::cmp_key_with_search_key(rownum_t): Assertion `!compare_pred[i]->null_value'
# failed with subquery on both sides of NOT IN and materialization
#
CREATE TABLE t1 (f1a int, f1b int) ;
INSERT IGNORE INTO t1 VALUES (1,1),(2,2);
CREATE TABLE t2 ( f2 int);
INSERT IGNORE INTO t2 VALUES (3),(4);
CREATE TABLE t3 (f3a int, f3b int);
set session optimizer_switch='materialization=on,partial_match_rowid_merge=on,partial_match_table_scan=off';
EXPLAIN
SELECT * FROM t2 WHERE (SELECT f3a FROM t3) NOT IN (SELECT f1a FROM t1);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 ALL NULL NULL NULL NULL 2 Using where
3 SUBQUERY t1 ALL NULL NULL NULL NULL 2
2 SUBQUERY t3 system NULL NULL NULL NULL 0 const row not found
SELECT * FROM t2 WHERE (SELECT f3a FROM t3) NOT IN (SELECT f1a FROM t1);
f2
EXPLAIN
SELECT * FROM t2 WHERE (SELECT f3a, f3b FROM t3) NOT IN (SELECT f1a, f1b FROM t1);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 ALL NULL NULL NULL NULL 2 Using where
3 SUBQUERY t1 ALL NULL NULL NULL NULL 2
2 SUBQUERY t3 system NULL NULL NULL NULL 0 const row not found
SELECT * FROM t2 WHERE (SELECT f3a, f3b FROM t3) NOT IN (SELECT f1a, f1b FROM t1);
f2
insert into t3 values (1,1),(2,2);
EXPLAIN
SELECT * FROM t2 WHERE (SELECT f3a FROM t3 where f3a > 3) NOT IN (SELECT f1a FROM t1);
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t2 ALL NULL NULL NULL NULL 2 Using where
3 SUBQUERY t1 ALL NULL NULL NULL NULL 2
2 SUBQUERY t3 ALL NULL NULL NULL NULL 2 Using where
SELECT * FROM t2 WHERE (SELECT f3a FROM t3 where f3a > 3) NOT IN (SELECT f1a FROM t1);
f2
3
4
drop table t1, t2, t3;

28
mysql-test/t/subselect_mat.test
View File

@ -1011,3 +1011,31 @@ SELECT pk FROM t1 WHERE (a) IN (SELECT a FROM t2 WHERE pk > 0);
SELECT pk FROM t1 WHERE (b,c,d) IN (SELECT b,c,d FROM t2 WHERE pk > 0);
DROP TABLE t1, t2;
--echo #
--echo # LPBUG#719198 Ordered_key::cmp_key_with_search_key(rownum_t): Assertion `!compare_pred[i]->null_value'
--echo # failed with subquery on both sides of NOT IN and materialization
--echo #
CREATE TABLE t1 (f1a int, f1b int) ;
INSERT IGNORE INTO t1 VALUES (1,1),(2,2);
CREATE TABLE t2 ( f2 int);
INSERT IGNORE INTO t2 VALUES (3),(4);
CREATE TABLE t3 (f3a int, f3b int);
set session optimizer_switch='materialization=on,partial_match_rowid_merge=on,partial_match_table_scan=off';
EXPLAIN
SELECT * FROM t2 WHERE (SELECT f3a FROM t3) NOT IN (SELECT f1a FROM t1);
SELECT * FROM t2 WHERE (SELECT f3a FROM t3) NOT IN (SELECT f1a FROM t1);
EXPLAIN
SELECT * FROM t2 WHERE (SELECT f3a, f3b FROM t3) NOT IN (SELECT f1a, f1b FROM t1);
SELECT * FROM t2 WHERE (SELECT f3a, f3b FROM t3) NOT IN (SELECT f1a, f1b FROM t1);
insert into t3 values (1,1),(2,2);
EXPLAIN
SELECT * FROM t2 WHERE (SELECT f3a FROM t3 where f3a > 3) NOT IN (SELECT f1a FROM t1);
SELECT * FROM t2 WHERE (SELECT f3a FROM t3 where f3a > 3) NOT IN (SELECT f1a FROM t1);
drop table t1, t2, t3;

7
sql/item.h
View File

@ -3342,6 +3342,13 @@ private:
};
/**
@todo
Implement the is_null() method for this class. Currently calling is_null()
on any Item_cache object resolves to Item::is_null(), which reutns FALSE
for any value.
*/
class Item_cache: public Item_basic_constant
{
protected:

2
sql/item_subselect.cc
View File

@ -5069,7 +5069,7 @@ bool subselect_rowid_merge_engine::partial_match()
for (uint i= test(non_null_key); i < keys_count; i++)
{
DBUG_ASSERT(merge_keys[i]->get_column_count() == 1);
if (merge_keys[i]->get_search_key(0)->is_null())
if (merge_keys[i]->get_search_key(0)->null_value)
{
++count_nulls_in_search_key;
bitmap_set_bit(&matching_outer_cols, merge_keys[i]->get_keyid());