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Bug #37894: Assertion in init_read_record_seq in handler.h line 1444

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Select with a "NULL NOT IN" condition containing complex
subselect from the same table as in the outer select failed
with an assertion.


The failure was caused by a concatenation of circumstances:
1) an inner select was optimized by make_join_statistics to use
   the QUICK_RANGE_SELECT access method (that implies an index
   scan of the table);
2) a subselect was independent (constant) from the outer select;
3) a condition was pushed down into inner select.

During the evaluation of a constant IN expression an optimizer
temporary changed the access method from index scan to table
scan, but an engine handler was already initialized for index
access by make_join_statistics. That caused an assertion.


Unnecessary index initialization has been removed from
the QUICK_RANGE_SELECT::init method (QUICK_RANGE_SELECT::reset
reinvokes this initialization).
This commit is contained in:
Gleb Shchepa
2008-10-10 15:27:58 +05:00
parent e7520c4b7e
commit 27f4c34beb
3 changed files with 39 additions and 1 deletions
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16
mysql-test/r/subselect3.result
View File

@ -779,4 +779,20 @@ SELECT 1 FROM t1 WHERE t1.a NOT IN (SELECT 1 FROM t1, t2 WHERE 0);
1
1
DROP TABLE t1, t2;
CREATE TABLE t1 (
pk INT PRIMARY KEY,
int_key INT,
varchar_key VARCHAR(5) UNIQUE,
varchar_nokey VARCHAR(5)
);
INSERT INTO t1 VALUES (9, 7,NULL,NULL), (10,8,'p' ,'p');
SELECT varchar_nokey
FROM t1
WHERE NULL NOT IN (
SELECT INNR.pk FROM t1 AS INNR2
LEFT JOIN t1 AS INNR ON ( INNR2.int_key = INNR.int_key )
WHERE INNR.varchar_key > 'n{'
);
varchar_nokey
DROP TABLE t1;
End of 5.0 tests

22
mysql-test/t/subselect3.test
View File

@ -618,4 +618,26 @@ SELECT 1 FROM t1 WHERE t1.a NOT IN (SELECT 1 FROM t1, t2 WHERE 0);
DROP TABLE t1, t2;
#
# Bug #37894: Assertion in init_read_record_seq in handler.h line 1444
#
CREATE TABLE t1 (
pk INT PRIMARY KEY,
int_key INT,
varchar_key VARCHAR(5) UNIQUE,
varchar_nokey VARCHAR(5)
);
INSERT INTO t1 VALUES (9, 7,NULL,NULL), (10,8,'p' ,'p');
SELECT varchar_nokey
FROM t1
WHERE NULL NOT IN (
SELECT INNR.pk FROM t1 AS INNR2
LEFT JOIN t1 AS INNR ON ( INNR2.int_key = INNR.int_key )
WHERE INNR.varchar_key > 'n{'
);
DROP TABLE t1;
--echo End of 5.0 tests

2
sql/opt_range.cc
View File

@ -1015,7 +1015,7 @@ int QUICK_RANGE_SELECT::init()
if (file->inited != handler::NONE)
file->ha_index_or_rnd_end();
DBUG_RETURN(error= file->ha_index_init(index));
DBUG_RETURN(FALSE);
}