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Merge mysql.com:/d2/hf/mrg/mysql-5.0-opt

into  mysql.com:/d2/hf/mrg/mysql-5.1-opt
This commit is contained in:
holyfoot/hf@hfmain.(none)
2007-05-18 20:00:49 +05:00
18 changed files with 701 additions and 22 deletions

View File

@@ -1321,4 +1321,51 @@ SELECT a,AVG(DISTINCT b) AS average FROM t1 GROUP BY a HAVING average > 50;
a average
1 32768.5000
DROP TABLE t1;
CREATE TABLE t1 ( a INT, b INT, KEY(a) );
INSERT INTO t1 VALUES (NULL, 1), (NULL, 2);
EXPLAIN SELECT MIN(a), MIN(b) FROM t1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 2
SELECT MIN(a), MIN(b) FROM t1;
MIN(a) MIN(b)
NULL 1
CREATE TABLE t2( a INT, b INT, c INT, KEY(a, b) );
INSERT INTO t2 ( a, b, c ) VALUES ( 1, NULL, 2 ), ( 1, 3, 4 ), ( 1, 4, 4 );
EXPLAIN SELECT MIN(b), MIN(c) FROM t2 WHERE a = 1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 ref a a 5 const 2 Using where
SELECT MIN(b), MIN(c) FROM t2 WHERE a = 1;
MIN(b) MIN(c)
3 2
CREATE TABLE t3 (a INT, b INT, c int, KEY(a, b));
INSERT INTO t3 VALUES (1, NULL, 1), (2, NULL, 2), (2, NULL, 2), (3, NULL, 3);
EXPLAIN SELECT MIN(a), MIN(b) FROM t3 where a = 2;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
SELECT MIN(a), MIN(b) FROM t3 where a = 2;
MIN(a) MIN(b)
2 NULL
CREATE TABLE t4 (a INT, b INT, c int, KEY(a, b));
INSERT INTO t4 VALUES (1, 1, 1), (2, NULL, 2), (2, NULL, 2), (3, 1, 3);
EXPLAIN SELECT MIN(a), MIN(b) FROM t4 where a = 2;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
SELECT MIN(a), MIN(b) FROM t4 where a = 2;
MIN(a) MIN(b)
2 NULL
SELECT MIN(b), min(c) FROM t4 where a = 2;
MIN(b) min(c)
NULL 2
CREATE TABLE t5( a INT, b INT, KEY( a, b) );
INSERT INTO t5 VALUES( 1, 1 ), ( 1, 2 );
EXPLAIN SELECT MIN(a), MIN(b) FROM t5 WHERE a = 1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE NULL NULL NULL NULL NULL NULL NULL Select tables optimized away
SELECT MIN(a), MIN(b) FROM t5 WHERE a = 1;
MIN(a) MIN(b)
1 1
SELECT MIN(a), MIN(b) FROM t5 WHERE a = 1 and b > 1;
MIN(a) MIN(b)
1 2
DROP TABLE t1, t2, t3, t4, t5;
End of 5.0 tests