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Merge bk-internal.mysql.com:/home/bk/mysql-4.0

Browse source 
into mysql.com:/home/kostja/mysql/mysql-4.0-1335
This commit is contained in:
konstantin@mysql.com 2003-12-10 01:15:31 +03:00
commit 8ee31c26f2
3 changed files with 66 additions and 3 deletions
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31
mysql-test/r/group_by.result
View file

@ -287,7 +287,7 @@ table type possible_keys key key_len ref rows Extra
t1 ALL NULL NULL NULL NULL 8 Using filesort
explain select sql_big_result spid,sum(userid) from t1 group by spid desc order by null;
table type possible_keys key key_len ref rows Extra
t1 ALL NULL NULL NULL NULL 8
t1 ALL NULL NULL NULL NULL 8 Using filesort
select sql_big_result spid,sum(userid) from t1 group by spid desc;
spid sum(userid)
7 3
@ -597,3 +597,32 @@ count(*) category
1 3
1 4
drop table t1;
CREATE TABLE t1 (
userid int(10) unsigned,
score smallint(5) unsigned,
key (score)
);
INSERT INTO t1 VALUES (1,1),(2,2),(1,1),(3,3),(3,3),(3,3),(3,3),(3,3);
SELECT userid,count(*) FROM t1 GROUP BY userid DESC;
userid count(*)
3 5
2 1
1 2
EXPLAIN SELECT userid,count(*) FROM t1 GROUP BY userid DESC;
table type possible_keys key key_len ref rows Extra
t1 ALL NULL NULL NULL NULL 8 Using temporary; Using filesort
DROP TABLE t1;
CREATE TABLE t1 (
i int(11) default NULL,
j int(11) default NULL
);
INSERT INTO t1 VALUES (1,2),(2,3),(4,5),(3,5),(1,5),(23,5);
SELECT i, COUNT(DISTINCT(i)) FROM t1 GROUP BY j ORDER BY NULL;
i COUNT(DISTINCT(i))
1 1
2 1
4 4
explain SELECT i, COUNT(DISTINCT(i)) FROM t1 GROUP BY j ORDER BY NULL;
table type possible_keys key key_len ref rows Extra
t1 ALL NULL NULL NULL NULL 6 Using filesort
DROP TABLE t1;

24
mysql-test/t/group_by.test
View file

@ -423,3 +423,27 @@ select id, sum(qty) as sqty, count(qty) as cqty from t1 group by id having sum(q
select count(*), case interval(qty,2,3,4,5,6,7,8) when -1 then NULL when 0 then "zero" when 1 then "one" when 2 then "two" end as category from t1 group by category;
select count(*), interval(qty,2,3,4,5,6,7,8) as category from t1 group by category;
drop table t1;
#
# Tests for bug #1355: 'Using filesort' is missing in EXPLAIN when ORDER BY
# NULL is used.
#
CREATE TABLE t1 (
userid int(10) unsigned,
score smallint(5) unsigned,
key (score)
);
INSERT INTO t1 VALUES (1,1),(2,2),(1,1),(3,3),(3,3),(3,3),(3,3),(3,3);
# Here we select unordered GROUP BY into a temporary talbe,
# and then sort it with filesort (GROUP BY in MySQL
# implies sorted order of results)
SELECT userid,count(*) FROM t1 GROUP BY userid DESC;
EXPLAIN SELECT userid,count(*) FROM t1 GROUP BY userid DESC;
DROP TABLE t1;
CREATE TABLE t1 (
i int(11) default NULL,
j int(11) default NULL
);
INSERT INTO t1 VALUES (1,2),(2,3),(4,5),(3,5),(1,5),(23,5);
SELECT i, COUNT(DISTINCT(i)) FROM t1 GROUP BY j ORDER BY NULL;
explain SELECT i, COUNT(DISTINCT(i)) FROM t1 GROUP BY j ORDER BY NULL;
DROP TABLE t1;

14
sql/sql_select.cc
View file

@ -696,8 +696,18 @@ mysql_select(THD *thd,TABLE_LIST *tables,List<Item> &fields,COND *conds,
if (select_options & SELECT_DESCRIBE)
{
if (!order && !no_order)
order=group;
/*
Check if we managed to optimize ORDER BY away and don't use temporary
table to resolve ORDER BY: in that case, we only may need to do
filesort for GROUP BY.
*/
if (!order && !no_order && (!skip_sort_order || !need_tmp))
{
/* Reset 'order' to 'group' and reinit variables describing 'order' */
order= group;
simple_order= simple_group;
skip_sort_order= 0;
}
if (order &&
(join.const_tables == join.tables ||
((simple_order || skip_sort_order) &&