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fix for the bug #2419: order by ignores rows.

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null_ref_key moved to TABLE_REF.
new null range created if necessary.
This commit is contained in:
ram@gw.mysql.r18.ru
2004-01-31 10:04:16 +04:00
parent d4d097689b
commit 6fab168a63
6 changed files with 65 additions and 12 deletions
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21
mysql-test/r/order_by.result
View File

@ -590,3 +590,24 @@ SELECT id FROM t1 WHERE id <11984 AND menu =2 ORDER BY id DESC LIMIT 1 ;
id
11392
drop table t1;
create table t1(a int, b int, index(b));
insert into t1 values (2, 1), (1, 1), (4, NULL), (3, NULL), (6, 2), (5, 2);
explain select * from t1 where b=1 or b is null order by a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref_or_null b b 5 const 3 Using where; Using filesort
select * from t1 where b=1 or b is null order by a;
a b
1 1
2 1
3 NULL
4 NULL
explain select * from t1 where b=2 or b is null order by a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ref_or_null b b 5 const 4 Using where; Using filesort
select * from t1 where b=2 or b is null order by a;
a b
3 NULL
4 NULL
5 2
6 2
drop table t1;

12
mysql-test/t/order_by.test
View File

@ -381,3 +381,15 @@ CREATE TABLE t1 ( id smallint(6) unsigned NOT NULL default '0', menu tinyint(4
INSERT INTO t1 VALUES (11384, 2),(11392, 2);
SELECT id FROM t1 WHERE id <11984 AND menu =2 ORDER BY id DESC LIMIT 1 ;
drop table t1;
#
# REF_OR_NULL optimization + filesort (bug #2419)
#
create table t1(a int, b int, index(b));
insert into t1 values (2, 1), (1, 1), (4, NULL), (3, NULL), (6, 2), (5, 2);
explain select * from t1 where b=1 or b is null order by a;
select * from t1 where b=1 or b is null order by a;
explain select * from t1 where b=2 or b is null order by a;
select * from t1 where b=2 or b is null order by a;
drop table t1;