Commit da416060 authored by igor@olga.mysql.com's avatar igor@olga.mysql.com
Browse files

Merge olga.mysql.com:/home/igor/mysql-5.0-opt 

into  olga.mysql.com:/home/igor/dev-opt/mysql-5.0-opt-bug25602
parents 684d0ced 59b9077c

mysql-test/r/group_min_max.result

+21 −0
Original line number Diff line number Diff line
@@ -2286,3 +2286,24 @@ Variable_name Value 
Handler_read_key	8

Handler_read_next	1

DROP TABLE t1,t2,t3;

CREATE TABLE t1 (a int, INDEX idx(a));

INSERT INTO t1 VALUES

(4), (2), (1), (2), (4), (2), (1), (4),

(4), (2), (1), (2), (2), (4), (1), (4);

EXPLAIN SELECT DISTINCT(a) FROM t1;

id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra

1	SIMPLE	t1	range	NULL	idx	5	NULL	9	Using index for group-by

SELECT DISTINCT(a) FROM t1;

a

1

2

4

EXPLAIN SELECT SQL_BIG_RESULT DISTINCT(a) FROM t1;

id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra

1	SIMPLE	t1	range	NULL	idx	5	NULL	9	Using index for group-by

SELECT SQL_BIG_RESULT DISTINCT(a) FROM t1;

a

1

2

4

DROP TABLE t1;

mysql-test/t/group_min_max.test

+22 −0
Original line number Diff line number Diff line
@@ -870,3 +870,25 @@ DELETE FROM t3 WHERE (SELECT (SELECT MAX(b) FROM t1 GROUP BY a HAVING a < 2) x 
SHOW STATUS LIKE 'handler_read__e%';



DROP TABLE t1,t2,t3;



#

# Bug#25602: queries with DISTINCT and SQL_BIG_RESULT hint 

#            for which loose scan optimization is applied

#



CREATE TABLE t1 (a int, INDEX idx(a));

INSERT INTO t1 VALUES

  (4), (2), (1), (2), (4), (2), (1), (4),

  (4), (2), (1), (2), (2), (4), (1), (4);



EXPLAIN SELECT DISTINCT(a) FROM t1;

SELECT DISTINCT(a) FROM t1;

EXPLAIN SELECT SQL_BIG_RESULT DISTINCT(a) FROM t1;

SELECT SQL_BIG_RESULT DISTINCT(a) FROM t1;



DROP TABLE t1;

sql/sql_select.cc

+6 −2
Original line number Diff line number Diff line
@@ -12551,10 +12551,14 @@ create_sort_index(THD *thd, JOIN *join, ORDER *order, 


  /*

    When there is SQL_BIG_RESULT do not sort using index for GROUP BY,

    and thus force sorting on disk.

    and thus force sorting on disk unless a group min-max optimization

    is going to be used as it is applied now only for one table queries

    with covering indexes.

  */

  if ((order != join->group_list || 

       !(join->select_options & SELECT_BIG_RESULT)) &&

       !(join->select_options & SELECT_BIG_RESULT) ||

       select && select->quick &&

       select->quick->get_type() == QUICK_SELECT_I::QS_TYPE_GROUP_MIN_MAX) &&

      test_if_skip_sort_order(tab,order,select_limit,0))

    DBUG_RETURN(0);

  for (ORDER *ord= join->order; ord; ord= ord->next)