Commit c394dbe1 authored by igor@olga.mysql.com's avatar igor@olga.mysql.com
Browse files

Fixed bug #32815. 

The index (key_part_1, key_part-2) was erroneously considered as compatible
with the required ordering in the function test_test_if_order_by_key when 
a query with an ORDER BY clause contained a condition of the form
  key_part_1=const OR key_part_1 IS NULL 
and the order list contained only key_part_2. This happened because the value
of the const_key_parts field in the KEYUSE structure was not formed correctly
for the keys that could be used for ref_or_null access. 
This was fixed in the code of the update_ref_and_keys function.
The problem could not manifest itself for MyISAM databases because the
implementation of the keys_to_use_for_scanning() handler function always
returns an empty bitmap for the MyISAM engine.
parent 55d6d04d

mysql-test/r/innodb_mysql.result

+12 −0
Original line number Diff line number Diff line
@@ -1213,4 +1213,16 @@ a b 
3	2

1	1

DROP TABLE t1;

CREATE TABLE t1 (id int, type char(6), d int, INDEX idx(id,d)) ENGINE=InnoDB;

INSERT INTO t1 VALUES 

(191, 'member', 1), (NULL, 'member', 3), (NULL, 'member', 4), (201, 'member', 2);

EXPLAIN SELECT * FROM t1 WHERE id=191 OR id IS NULL ORDER BY d;

id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra

1	SIMPLE	t1	ALL	idx	NULL	NULL	NULL	3	Using where; Using filesort

SELECT * FROM t1 WHERE id=191 OR id IS NULL ORDER BY d;

id	type	d

191	member	1

NULL	member	3

NULL	member	4

DROP TABLE t1;

End of 5.0 tests

mysql-test/t/innodb_mysql.test

+15 −0
Original line number Diff line number Diff line
@@ -960,4 +960,19 @@ SELECT * FROM t1 ORDER BY b DESC, a ASC; 


DROP TABLE t1;



#

# Bug #32815: query with ORDER BY and a possible ref_or_null access

#



CREATE TABLE t1 (id int, type char(6), d int, INDEX idx(id,d)) ENGINE=InnoDB;

INSERT INTO t1 VALUES 

  (191, 'member', 1), (NULL, 'member', 3), (NULL, 'member', 4), (201, 'member', 2); 



EXPLAIN SELECT * FROM t1 WHERE id=191 OR id IS NULL ORDER BY d;

SELECT * FROM t1 WHERE id=191 OR id IS NULL ORDER BY d;



DROP TABLE t1;







--echo End of 5.0 tests

sql/sql_select.cc

+1 −1
Original line number Diff line number Diff line
@@ -3691,7 +3691,7 @@ update_ref_and_keys(THD *thd, DYNAMIC_ARRAY *keyuse,JOIN_TAB *join_tab, 
    found_eq_constant=0;

    for (i=0 ; i < keyuse->elements-1 ; i++,use++)

    {

      if (!use->used_tables)

      if (!use->used_tables && use->optimize != KEY_OPTIMIZE_REF_OR_NULL)

	use->table->const_key_parts[use->key]|= use->keypart_map;

      if (use->keypart != FT_KEYPART)

      {