mirror of
https://github.com/MariaDB/server.git
synced 2025-07-29 05:21:33 +03:00
Bug#17909656 - WRONG RESULTS FOR A SIMPLE QUERY WITH GROUP BY
Problem: If there is a predicate on a column referenced by MIN/MAX and that predicate is not present in all the disjunctions on keyparts earlier in the compound index, Loose Index Scan will not return correct result. Analysis: When loose index scan is chosen, range optimizer currently groups all the predicates that contain group parts separately and minmax parts separately. It therefore applies all the conditions on the group parts first to the fetched row. Then in the call to next_max, it processes the conditions which have min/max keypart. For ex in the following query: Select f1, max(f2) from t1 where (f1 = 10 and f2 = 13) or (f1 = 3) group by f1; Condition (f2 = 13) would be applied even for rows that satisfy (f1 = 3) thereby giving wrong results. Solution: Do not choose loose_index_scan for such cases. So a new rule WA2 is introduced to take care of the same. WA2: "If there are predicates on C, these predicates must be in conjuction to all predicates on all earlier keyparts in I." Todo the same, fix reuses the function get_constant_key_infix(). Since this funciton will fail for all multi-range conditions, it is re-written to recognize that if the sub-conditions are equivalent across the disjuncts: it will now succeed. And to achieve this a new helper function is introduced called all_same(). The fix also moves the test of NGA3 up to the former only caller, get_constant_key_infix(). mysql-test/r/group_min_max_innodb.result: Added test result change for Bug#17909656 mysql-test/t/group_min_max_innodb.test: Added test cases for Bug#17909656 sql/opt_range.cc: Introduced Rule WA2 because of Bug#17909656
This commit is contained in:
Chaithra Gopalareddy
@ -118,3 +118,171 @@ COUNT(DISTINCT a)
|
||||
1
|
||||
DROP TABLE t1;
|
||||
End of 5.5 tests
|
||||
#
|
||||
# Bug#17909656 - WRONG RESULTS FOR A SIMPLE QUERY WITH GROUP BY
|
||||
#
|
||||
CREATE TABLE t0 (
|
||||
i1 INTEGER NOT NULL
|
||||
);
|
||||
INSERT INTO t0 VALUES (1),(2),(3),(4),(5),(6),(7),(8),(9),(10),
|
||||
(11),(12),(13),(14),(15),(16),(17),(18),(19),(20),
|
||||
(21),(22),(23),(24),(25),(26),(27),(28),(29),(30);
|
||||
CREATE TABLE t1 (
|
||||
c1 CHAR(1) NOT NULL,
|
||||
i1 INTEGER NOT NULL,
|
||||
i2 INTEGER NOT NULL,
|
||||
UNIQUE KEY k1 (c1,i2)
|
||||
) ENGINE=InnoDB;
|
||||
INSERT INTO t1 SELECT 'A',i1,i1 FROM t0;
|
||||
INSERT INTO t1 SELECT 'B',i1,i1 FROM t0;
|
||||
INSERT INTO t1 SELECT 'C',i1,i1 FROM t0;
|
||||
INSERT INTO t1 SELECT 'D',i1,i1 FROM t0;
|
||||
INSERT INTO t1 SELECT 'E',i1,i1 FROM t0;
|
||||
INSERT INTO t1 SELECT 'F',i1,i1 FROM t0;
|
||||
CREATE TABLE t2 (
|
||||
c1 CHAR(1) NOT NULL,
|
||||
i1 INTEGER NOT NULL,
|
||||
i2 INTEGER NOT NULL,
|
||||
UNIQUE KEY k2 (c1,i1,i2)
|
||||
) ENGINE=InnoDB;
|
||||
INSERT INTO t2 SELECT 'A',i1,i1 FROM t0;
|
||||
INSERT INTO t2 SELECT 'B',i1,i1 FROM t0;
|
||||
INSERT INTO t2 SELECT 'C',i1,i1 FROM t0;
|
||||
INSERT INTO t2 SELECT 'D',i1,i1 FROM t0;
|
||||
INSERT INTO t2 SELECT 'E',i1,i1 FROM t0;
|
||||
INSERT INTO t2 SELECT 'F',i1,i1 FROM t0;
|
||||
ANALYZE TABLE t1;
|
||||
ANALYZE TABLE t2;
|
||||
EXPLAIN SELECT c1, max(i2) FROM t1 WHERE (c1 = 'C' AND i2 = 17) OR ( c1 = 'F')
|
||||
GROUP BY c1;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t1 range k1 k1 5 NULL 31 Using where; Using index
|
||||
SELECT c1, max(i2) FROM t1 WHERE (c1 = 'C' AND i2 = 17) OR ( c1 = 'F')
|
||||
GROUP BY c1;
|
||||
c1 max(i2)
|
||||
C 17
|
||||
F 30
|
||||
EXPLAIN SELECT c1, max(i2) FROM t1 WHERE (c1 = 'C' OR ( c1 = 'F' AND i2 = 17))
|
||||
GROUP BY c1;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t1 range k1 k1 5 NULL 31 Using where; Using index
|
||||
SELECT c1, max(i2) FROM t1 WHERE (c1 = 'C' OR ( c1 = 'F' AND i2 = 17))
|
||||
GROUP BY c1;
|
||||
c1 max(i2)
|
||||
C 30
|
||||
F 17
|
||||
EXPLAIN SELECT c1, max(i2) FROM t1 WHERE (c1 = 'C' OR c1 = 'F' ) AND ( i2 = 17 )
|
||||
GROUP BY c1;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t1 range k1 k1 5 NULL 1 Using where; Using index for group-by
|
||||
SELECT c1, max(i2) FROM t1 WHERE (c1 = 'C' OR c1 = 'F' ) AND ( i2 = 17 )
|
||||
GROUP BY c1;
|
||||
c1 max(i2)
|
||||
C 17
|
||||
F 17
|
||||
EXPLAIN SELECT c1, max(i2) FROM t1
|
||||
WHERE ((c1 = 'C' AND (i2 = 40 OR i2 = 30)) OR ( c1 = 'F' AND (i2 = 40 )))
|
||||
GROUP BY c1;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t1 range k1 k1 5 NULL 3 Using where; Using index
|
||||
SELECT c1, max(i2) FROM t1
|
||||
WHERE ((c1 = 'C' AND (i2 = 40 OR i2 = 30)) OR ( c1 = 'F' AND (i2 = 40 )))
|
||||
GROUP BY c1;
|
||||
c1 max(i2)
|
||||
C 30
|
||||
EXPLAIN SELECT c1, i1, max(i2) FROM t2
|
||||
WHERE (c1 = 'C' OR ( c1 = 'F' AND i1 < 35)) AND ( i2 = 17 )
|
||||
GROUP BY c1,i1;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t2 range k2 k2 9 NULL 59 Using where; Using index for group-by
|
||||
SELECT c1, i1, max(i2) FROM t2
|
||||
WHERE (c1 = 'C' OR ( c1 = 'F' AND i1 < 35)) AND ( i2 = 17 )
|
||||
GROUP BY c1,i1;
|
||||
c1 i1 max(i2)
|
||||
C 17 17
|
||||
F 17 17
|
||||
EXPLAIN SELECT c1, i1, max(i2) FROM t2
|
||||
WHERE (((c1 = 'C' AND i1 < 40) OR ( c1 = 'F' AND i1 < 35)) AND ( i2 = 17 ))
|
||||
GROUP BY c1,i1;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t2 range k2 k2 9 NULL 58 Using where; Using index for group-by
|
||||
SELECT c1, i1, max(i2) FROM t2
|
||||
WHERE (((c1 = 'C' AND i1 < 40) OR ( c1 = 'F' AND i1 < 35)) AND ( i2 = 17 ))
|
||||
GROUP BY c1,i1;
|
||||
c1 i1 max(i2)
|
||||
C 17 17
|
||||
F 17 17
|
||||
EXPLAIN SELECT c1, i1, max(i2) FROM t2
|
||||
WHERE ((c1 = 'C' AND i1 < 40) OR ( c1 = 'F' AND i1 < 35) OR ( i2 = 17 ))
|
||||
GROUP BY c1,i1;
|
||||
id select_type table type possible_keys key key_len ref rows Extra
|
||||
1 SIMPLE t2 range k2 k2 5 NULL 181 Using where; Using index for group-by
|
||||
SELECT c1, i1, max(i2) FROM t2
|
||||
WHERE ((c1 = 'C' AND i1 < 40) OR ( c1 = 'F' AND i1 < 35) OR ( i2 = 17 ))
|
||||
GROUP BY c1,i1;
|
||||
c1 i1 max(i2)
|
||||
A 17 17
|
||||
B 17 17
|
||||
C 1 1
|
||||
C 2 2
|
||||
C 3 3
|
||||
C 4 4
|
||||
C 5 5
|
||||
C 6 6
|
||||
C 7 7
|
||||
C 8 8
|
||||
C 9 9
|
||||
C 10 10
|
||||
C 11 11
|
||||
C 12 12
|
||||
C 13 13
|
||||
C 14 14
|
||||
C 15 15
|
||||
C 16 16
|
||||
C 17 17
|
||||
C 18 18
|
||||
C 19 19
|
||||
C 20 20
|
||||
C 21 21
|
||||
C 22 22
|
||||
C 23 23
|
||||
C 24 24
|
||||
C 25 25
|
||||
C 26 26
|
||||
C 27 27
|
||||
C 28 28
|
||||
C 29 29
|
||||
C 30 30
|
||||
D 17 17
|
||||
E 17 17
|
||||
F 1 1
|
||||
F 2 2
|
||||
F 3 3
|
||||
F 4 4
|
||||
F 5 5
|
||||
F 6 6
|
||||
F 7 7
|
||||
F 8 8
|
||||
F 9 9
|
||||
F 10 10
|
||||
F 11 11
|
||||
F 12 12
|
||||
F 13 13
|
||||
F 14 14
|
||||
F 15 15
|
||||
F 16 16
|
||||
F 17 17
|
||||
F 18 18
|
||||
F 19 19
|
||||
F 20 20
|
||||
F 21 21
|
||||
F 22 22
|
||||
F 23 23
|
||||
F 24 24
|
||||
F 25 25
|
||||
F 26 26
|
||||
F 27 27
|
||||
F 28 28
|
||||
F 29 29
|
||||
F 30 30
|
||||
DROP TABLE t0,t1,t2;
|
||||
|
||||
Reference in New Issue
Block a user