explain select count(distinct a1,a2,b) from t1 where (a2 >= 'b') and (b = 'a');
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL idx_t1_2 147 NULL 128 Using where; Using index
1 SIMPLE t1 range NULL idx_t1_1 147 NULL 17 Using where; Using index for group-by
explain select count(distinct a1,a2,b,c) from t1 where (a2 >= 'b') and (b = 'a') and (c = 'i121');
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL idx_t1_1 163 NULL 128 Using where; Using index
1 SIMPLE t1 range NULL idx_t1_1 163 NULL 65 Using where; Using index for group-by (scanning)
explain extended select count(distinct a1,a2,b) from t1 where (a1 > 'a') and (a2 > 'a') and (b = 'c');
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 index idx_t1_0,idx_t1_1,idx_t1_2 idx_t1_2 147 NULL 128 75.00 Using where; Using index
1 SIMPLE t1 range idx_t1_0,idx_t1_1,idx_t1_2 idx_t1_1 147 NULL 14 100.00 Using where; Using index for group-by
Warnings:
Note 1003 select count(distinct `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`) AS `count(distinct a1,a2,b)` from `test`.`t1` where ((`test`.`t1`.`b` = 'c') and (`test`.`t1`.`a1` > 'a') and (`test`.`t1`.`a2` > 'a'))
explain select count(distinct b) from t1 where (a2 >= 'b') and (b = 'a');
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL idx_t1_2 147 NULL 128 Using where; Using index
explain extended select ord(a1) + count(distinct a1,a2,b) from t1 where (a1 > 'a') and (a2 > 'a');
explain extended select 98 + count(distinct a1,a2,b) from t1 where (a1 > 'a') and (a2 > 'a');
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t1 index idx_t1_0,idx_t1_1,idx_t1_2 idx_t1_2 147 NULL 128 75.00 Using where; Using index
1 SIMPLE t1 range idx_t1_0,idx_t1_1,idx_t1_2 idx_t1_1 147 NULL 14 100.00 Using where; Using index for group-by
Warnings:
Note 1003 select (ord(`test`.`t1`.`a1`) + count(distinct `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`)) AS `ord(a1) + count(distinct a1,a2,b)` from `test`.`t1` where ((`test`.`t1`.`a1` > 'a') and (`test`.`t1`.`a2` > 'a'))
Note 1003 select (98 + count(distinct `test`.`t1`.`a1`,`test`.`t1`.`a2`,`test`.`t1`.`b`)) AS `98 + count(distinct a1,a2,b)` from `test`.`t1` where ((`test`.`t1`.`a1` > 'a') and (`test`.`t1`.`a2` > 'a'))
select count(distinct a1,a2,b) from t1 where (a2 >= 'b') and (b = 'a');
count(distinct a1,a2,b)
4
@ -1829,8 +1829,8 @@ count(distinct a1,a2,b)
select count(distinct b) from t1 where (a2 >= 'b') and (b = 'a');
count(distinct b)
1
select ord(a1) + count(distinct a1,a2,b) from t1 where (a1 > 'a') and (a2 > 'a');
ord(a1) + count(distinct a1,a2,b)
select 98 + count(distinct a1,a2,b) from t1 where (a1 > 'a') and (a2 > 'a');
98 + count(distinct a1,a2,b)
104
explain select a1,a2,b, concat(min(c), max(c)) from t1 where a1 < 'd' group by a1,a2,b;
id select_type table type possible_keys key key_len ref rows Extra
@ -2514,3 +2514,257 @@ a MAX(b)
2 1
DROP TABLE t;
End of 5.1 tests
#
# WL#3220 (Loose index scan for COUNT DISTINCT)
#
CREATE TABLE t1 (a INT, b INT, c INT, KEY (a,b));
INSERT INTO t1 VALUES (1,1,1), (1,2,1), (1,3,1), (1,4,1);
INSERT INTO t1 SELECT a, b + 4, 1 FROM t1;
INSERT INTO t1 SELECT a + 1, b, 1 FROM t1;
CREATE TABLE t2 (a INT, b INT, c INT, d INT, e INT, f INT, KEY (a,b,c));
INSERT INTO t2 VALUES (1,1,1,1,1,1), (1,2,1,1,1,1), (1,3,1,1,1,1),
(1,4,1,1,1,1);
INSERT INTO t2 SELECT a, b + 4, c,d,e,f FROM t2;
INSERT INTO t2 SELECT a + 1, b, c,d,e,f FROM t2;
EXPLAIN SELECT COUNT(DISTINCT a) FROM t1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range NULL a 5 NULL 9 Using index for group-by
SELECT COUNT(DISTINCT a) FROM t1;
COUNT(DISTINCT a)
2
EXPLAIN SELECT COUNT(DISTINCT a,b) FROM t1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range NULL a 10 NULL 9 Using index for group-by
SELECT COUNT(DISTINCT a,b) FROM t1;
COUNT(DISTINCT a,b)
16
EXPLAIN SELECT COUNT(DISTINCT b,a) FROM t1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range NULL a 10 NULL 9 Using index for group-by
SELECT COUNT(DISTINCT b,a) FROM t1;
COUNT(DISTINCT b,a)
16
EXPLAIN SELECT COUNT(DISTINCT b) FROM t1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL a 10 NULL 16 Using index
SELECT COUNT(DISTINCT b) FROM t1;
COUNT(DISTINCT b)
8
EXPLAIN SELECT COUNT(DISTINCT a) FROM t1 GROUP BY a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range NULL a 5 NULL 9 Using index for group-by
SELECT COUNT(DISTINCT a) FROM t1 GROUP BY a;
COUNT(DISTINCT a)
1
1
EXPLAIN SELECT COUNT(DISTINCT b) FROM t1 GROUP BY a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range NULL a 10 NULL 9 Using index for group-by
SELECT COUNT(DISTINCT b) FROM t1 GROUP BY a;
COUNT(DISTINCT b)
8
8
EXPLAIN SELECT COUNT(DISTINCT a) FROM t1 GROUP BY b;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL a 10 NULL 16 Using index; Using filesort
SELECT COUNT(DISTINCT a) FROM t1 GROUP BY b;
COUNT(DISTINCT a)
2
2
2
2
2
2
2
2
EXPLAIN SELECT DISTINCT COUNT(DISTINCT a) FROM t1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL a 10 NULL 16 Using index
SELECT DISTINCT COUNT(DISTINCT a) FROM t1;
COUNT(DISTINCT a)
2
EXPLAIN SELECT COUNT(DISTINCT a, b + 0) FROM t1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 index NULL a 10 NULL 16 Using index
SELECT COUNT(DISTINCT a, b + 0) FROM t1;
COUNT(DISTINCT a, b + 0)
16
EXPLAIN SELECT COUNT(DISTINCT a) FROM t1 HAVING COUNT(DISTINCT b) < 10;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range NULL a 10 NULL 9 Using index for group-by
SELECT COUNT(DISTINCT a) FROM t1 HAVING COUNT(DISTINCT b) < 10;
COUNT(DISTINCT a)
EXPLAIN SELECT COUNT(DISTINCT a) FROM t1 HAVING COUNT(DISTINCT c) < 10;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 16
SELECT COUNT(DISTINCT a) FROM t1 HAVING COUNT(DISTINCT c) < 10;
COUNT(DISTINCT a)
2
EXPLAIN SELECT 1 FROM t1 HAVING COUNT(DISTINCT a) < 10;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range NULL a 5 NULL 9 Using index for group-by
SELECT 1 FROM t1 HAVING COUNT(DISTINCT a) < 10;
1
1
EXPLAIN SELECT 1 FROM t1 GROUP BY a HAVING COUNT(DISTINCT b) > 1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range NULL a 10 NULL 9 Using index for group-by
SELECT 1 FROM t1 GROUP BY a HAVING COUNT(DISTINCT b) > 1;
1
1
1
EXPLAIN SELECT COUNT(DISTINCT t1_1.a) FROM t1 t1_1, t1 t1_2 GROUP BY t1_1.a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1_1 index NULL a 10 NULL 16 Using index; Using temporary; Using filesort
1 SIMPLE t1_2 index NULL a 10 NULL 16 Using index; Using join buffer
SELECT COUNT(DISTINCT t1_1.a) FROM t1 t1_1, t1 t1_2 GROUP BY t1_1.a;
COUNT(DISTINCT t1_1.a)
1
1
EXPLAIN SELECT COUNT(DISTINCT a), 12 FROM t1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 range NULL a 5 NULL 9 Using index for group-by
SELECT COUNT(DISTINCT a), 12 FROM t1;
COUNT(DISTINCT a) 12
2 12
EXPLAIN SELECT COUNT(DISTINCT a, b, c) FROM t2;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range NULL a 15 NULL 9 Using index for group-by
SELECT COUNT(DISTINCT a, b, c) FROM t2;
COUNT(DISTINCT a, b, c)
16
EXPLAIN SELECT COUNT(DISTINCT a), SUM(DISTINCT a), AVG(DISTINCT a) FROM t2;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range NULL a 5 NULL 9 Using index for group-by
SELECT COUNT(DISTINCT a), SUM(DISTINCT a), AVG(DISTINCT a) FROM t2;
COUNT(DISTINCT a) SUM(DISTINCT a) AVG(DISTINCT a)
2 3 1.5000
EXPLAIN SELECT COUNT(DISTINCT a), SUM(DISTINCT a), AVG(DISTINCT f) FROM t2;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 ALL NULL NULL NULL NULL 16
SELECT COUNT(DISTINCT a), SUM(DISTINCT a), AVG(DISTINCT f) FROM t2;
COUNT(DISTINCT a) SUM(DISTINCT a) AVG(DISTINCT f)
2 3 1.0000
EXPLAIN SELECT COUNT(DISTINCT a, b), COUNT(DISTINCT b, a) FROM t2;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range NULL a 10 NULL 9 Using index for group-by
SELECT COUNT(DISTINCT a, b), COUNT(DISTINCT b, a) FROM t2;
COUNT(DISTINCT a, b) COUNT(DISTINCT b, a)
16 16
EXPLAIN SELECT COUNT(DISTINCT a, b), COUNT(DISTINCT b, f) FROM t2;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 ALL NULL NULL NULL NULL 16
SELECT COUNT(DISTINCT a, b), COUNT(DISTINCT b, f) FROM t2;
COUNT(DISTINCT a, b) COUNT(DISTINCT b, f)
16 8
EXPLAIN SELECT COUNT(DISTINCT a, b), COUNT(DISTINCT b, d) FROM t2;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 ALL NULL NULL NULL NULL 16
SELECT COUNT(DISTINCT a, b), COUNT(DISTINCT b, d) FROM t2;
COUNT(DISTINCT a, b) COUNT(DISTINCT b, d)
16 8
EXPLAIN SELECT a, c, COUNT(DISTINCT c, a, b) FROM t2 GROUP BY a, b, c;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range NULL a 15 NULL 9 Using index for group-by
SELECT a, c, COUNT(DISTINCT c, a, b) FROM t2 GROUP BY a, b, c;
a c COUNT(DISTINCT c, a, b)
1 1 1
1 1 1
1 1 1
1 1 1
1 1 1
1 1 1
1 1 1
2 1 1
2 1 1
2 1 1
2 1 1
2 1 1
2 1 1
2 1 1
2 1 1
2 1 1
EXPLAIN SELECT COUNT(DISTINCT c, a, b) FROM t2
WHERE a > 5 AND b BETWEEN 10 AND 20 GROUP BY a, b, c;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range a a 15 NULL 1 Using where; Using index for group-by
SELECT COUNT(DISTINCT c, a, b) FROM t2
WHERE a > 5 AND b BETWEEN 10 AND 20 GROUP BY a, b, c;
COUNT(DISTINCT c, a, b)
EXPLAIN SELECT COUNT(DISTINCT b), SUM(DISTINCT b) FROM t2 WHERE a = 5
GROUP BY b;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 ref a a 5 const 1 Using where; Using index
SELECT COUNT(DISTINCT b), SUM(DISTINCT b) FROM t2 WHERE a = 5
GROUP BY b;
COUNT(DISTINCT b) SUM(DISTINCT b)
EXPLAIN SELECT a, COUNT(DISTINCT b), SUM(DISTINCT b) FROM t2 GROUP BY a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range NULL a 10 NULL 9 Using index for group-by
SELECT a, COUNT(DISTINCT b), SUM(DISTINCT b) FROM t2 GROUP BY a;
a COUNT(DISTINCT b) SUM(DISTINCT b)
2 8 36
2 8 36
EXPLAIN SELECT COUNT(DISTINCT b), SUM(DISTINCT b) FROM t2 GROUP BY a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range NULL a 10 NULL 9 Using index for group-by
SELECT COUNT(DISTINCT b), SUM(DISTINCT b) FROM t2 GROUP BY a;
COUNT(DISTINCT b) SUM(DISTINCT b)
8 36
8 36
EXPLAIN SELECT COUNT(DISTINCT a, b) FROM t2 WHERE c = 13 AND d = 42;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 ALL NULL NULL NULL NULL 16 Using where
SELECT COUNT(DISTINCT a, b) FROM t2 WHERE c = 13 AND d = 42;
COUNT(DISTINCT a, b)
0
EXPLAIN SELECT a, COUNT(DISTINCT a), SUM(DISTINCT a) FROM t2
WHERE b = 13 AND c = 42 GROUP BY a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range NULL a 15 NULL 9 Using where; Using index for group-by
SELECT a, COUNT(DISTINCT a), SUM(DISTINCT a) FROM t2
WHERE b = 13 AND c = 42 GROUP BY a;
a COUNT(DISTINCT a) SUM(DISTINCT a)
EXPLAIN SELECT COUNT(DISTINCT a, b), SUM(DISTINCT a) FROM t2 WHERE b = 42;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range NULL a 10 NULL 9 Using where; Using index for group-by
SELECT COUNT(DISTINCT a, b), SUM(DISTINCT a) FROM t2 WHERE b = 42;
COUNT(DISTINCT a, b) SUM(DISTINCT a)
0 NULL
EXPLAIN SELECT SUM(DISTINCT a), MAX(b) FROM t2 GROUP BY a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range NULL a 5 NULL 9 Using index for group-by
SELECT SUM(DISTINCT a), MAX(b) FROM t2 GROUP BY a;
SUM(DISTINCT a) MAX(b)
1 8
2 8
EXPLAIN SELECT 42 * (a + c + COUNT(DISTINCT c, a, b)) FROM t2 GROUP BY a, b, c;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range NULL a 15 NULL 9 Using index for group-by
SELECT 42 * (a + c + COUNT(DISTINCT c, a, b)) FROM t2 GROUP BY a, b, c;
42 * (a + c + COUNT(DISTINCT c, a, b))
126
126
126
126
126
126
126
168
168
168
168
168
168
168
168
168
EXPLAIN SELECT (SUM(DISTINCT a) + MAX(b)) FROM t2 GROUP BY a;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t2 range NULL a 5 NULL 9 Using index for group-by
SELECT (SUM(DISTINCT a) + MAX(b)) FROM t2 GROUP BY a;