1berry/MariaDB-server
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Merge gkodinov@bk-internal.mysql.com:/home/bk/mysql-5.1-opt

Browse Source 
into  rakia.gmz:/home/kgeorge/mysql/autopush/B16590-5.1-opt
This commit is contained in:
gkodinov/kgeorge@rakia.gmz 2007-01-22 12:58:14 +02:00
commit c9df1caac8
3 changed files with 38 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
mysql-test/r/order_by.result
View File

@ -926,3 +926,12 @@ NULL
2
3
DROP TABLE t1,t2,t3,t4;
CREATE TABLE t1 (a INT, b INT, PRIMARY KEY (a), UNIQUE KEY b (b));
INSERT INTO t1 VALUES (1,1),(2,2);
CREATE TABLE t2 (a INT, b INT, KEY a (a,b));
INSERT INTO t2 VALUES (1,1),(1,2),(2,1),(2,2);
EXPLAIN SELECT 1 FROM t1,t2 WHERE t1.b=2 AND t1.a=t2.a ORDER BY t2.b;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 const PRIMARY,b b 5 const 1
1 SIMPLE t2 ref a a 5 const 2 Using where; Using index
DROP TABLE t1,t2;

13
mysql-test/t/order_by.test
View File

@ -640,3 +640,16 @@ SELECT t2.b FROM t1 LEFT JOIN (t2, t3 LEFT JOIN t4 ON t3.a=t4.a)
ON (t1.a=t2.a AND t1.b=t3.b) order by t2.b;
DROP TABLE t1,t2,t3,t4;
#
# BUG#16590: Optimized does not do right "const" table pre-read
#
CREATE TABLE t1 (a INT, b INT, PRIMARY KEY (a), UNIQUE KEY b (b));
INSERT INTO t1 VALUES (1,1),(2,2);
CREATE TABLE t2 (a INT, b INT, KEY a (a,b));
INSERT INTO t2 VALUES (1,1),(1,2),(2,1),(2,2);
EXPLAIN SELECT 1 FROM t1,t2 WHERE t1.b=2 AND t1.a=t2.a ORDER BY t2.b;
DROP TABLE t1,t2;

16
sql/sql_select.cc
View File

@ -7722,6 +7722,22 @@ static void update_const_equal_items(COND *cond, JOIN_TAB *tab)
key_map possible_keys= field->key_start;
possible_keys.intersect(field->table->keys_in_use_for_query);
stat[0].const_keys.merge(possible_keys);
/*
For each field in the multiple equality (for which we know that it
is a constant) we have to find its corresponding key part, and set
that key part in const_key_parts.
*/
if (!possible_keys.is_clear_all())
{
TABLE *tab= field->table;
KEYUSE *use;
for (use= stat->keyuse; use && use->table == tab; use++)
if (possible_keys.is_set(use->key) &&
tab->key_info[use->key].key_part[use->keypart].field ==
field)
tab->const_key_parts[use->key]|= use->keypart_map;
}
}
}
}