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mariadb/mysql-test/main/single_delete_update.result
Michael Widenius a7abddeffa Create 'main' test directory and move 't' and 'r' there
2018-03-29 13:59:44 +03:00

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#
# Bug #30584: delete with order by and limit clauses does not use
# limit efficiently
#
CREATE TABLE t1 (i INT);
INSERT INTO t1 VALUES (10),(11),(12),(13),(14),(15),(16),(17),(18),(19),
(20),(21),(22),(23),(24),(25);
CREATE TABLE t2(a INT, i INT PRIMARY KEY);
INSERT INTO t2 (i) SELECT i FROM t1;
FLUSH STATUS;
SELECT * FROM t2 WHERE i > 10 AND i <= 18 ORDER BY i LIMIT 5;
a i
NULL 11
NULL 12
NULL 13
NULL 14
NULL 15
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 0
Sort_range 0
Sort_rows 0
Sort_scan 0
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 1
Handler_read_last 0
Handler_read_next 4
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 0
Handler_read_rnd_deleted 0
Handler_read_rnd_next 0
FLUSH STATUS;
DELETE FROM t2 WHERE i > 10 AND i <= 18 ORDER BY i LIMIT 5;
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 0
Sort_range 0
Sort_rows 0
Sort_scan 0
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 1
Handler_read_last 0
Handler_read_next 4
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 0
Handler_read_rnd_deleted 0
Handler_read_rnd_next 0
SELECT * FROM t2 WHERE i > 10 AND i <= 18 ORDER BY i;
a i
NULL 16
NULL 17
NULL 18
DROP TABLE t2;
#
# index on field prefix:
#
CREATE TABLE t2(a INT, i CHAR(2), INDEX(i(1)));
INSERT INTO t2 (i) SELECT i FROM t1;
FLUSH STATUS;
SELECT * FROM t2 WHERE i > 10 AND i <= 18 ORDER BY i LIMIT 5;
a i
NULL 11
NULL 12
NULL 13
NULL 14
NULL 15
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 1
Sort_range 0
Sort_rows 5
Sort_scan 1
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 0
Handler_read_last 0
Handler_read_next 0
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 0
Handler_read_rnd_deleted 0
Handler_read_rnd_next 17
FLUSH STATUS;
DELETE FROM t2 WHERE i > 10 AND i <= 18 ORDER BY i LIMIT 5;
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 0
Sort_range 0
Sort_rows 8
Sort_scan 1
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 0
Handler_read_last 0
Handler_read_next 0
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 5
Handler_read_rnd_deleted 0
Handler_read_rnd_next 17
SELECT * FROM t2 WHERE i > 10 AND i <= 18 ORDER BY i;
a i
NULL 16
NULL 17
NULL 18
DROP TABLE t2;
#
# constant inside ORDER BY list, should use filesort
# on a small table
#
CREATE TABLE t2(a INT, b INT, c INT, d INT, INDEX(a, b, c));
INSERT INTO t2 (a, b, c) SELECT i, i, i FROM t1;
FLUSH STATUS;
SELECT * FROM t2 WHERE b = 10 ORDER BY a, c LIMIT 5;
a b c d
10 10 10 NULL
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 1
Sort_range 0
Sort_rows 1
Sort_scan 1
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 0
Handler_read_last 0
Handler_read_next 0
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 0
Handler_read_rnd_deleted 0
Handler_read_rnd_next 17
FLUSH STATUS;
DELETE FROM t2 WHERE b = 10 ORDER BY a, c LIMIT 5;
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 0
Sort_range 0
Sort_rows 1
Sort_scan 1
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 0
Handler_read_last 0
Handler_read_next 0
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 1
Handler_read_rnd_deleted 0
Handler_read_rnd_next 17
## should be 5 (previous LIMIT)
SELECT 1 - COUNT(*) FROM t2 WHERE b = 10;
1 - COUNT(*)
1
DROP TABLE t2;
#
# same test as above (constant inside ORDER BY list), but with
# a larger table - should not use filesort
#
CREATE TABLE t2(a INT, b INT, c INT, d INT, INDEX(a, b, c));
INSERT INTO t2 (a, b, c) SELECT i, i, i FROM t1;
INSERT INTO t2 (a, b, c) SELECT t1.i, t1.i, t1.i FROM t1, t1 x1, t1 x2;
FLUSH STATUS;
SELECT * FROM t2 WHERE b = 10 ORDER BY a, c LIMIT 5;
a b c d
10 10 10 NULL
10 10 10 NULL
10 10 10 NULL
10 10 10 NULL
10 10 10 NULL
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 0
Sort_range 0
Sort_rows 0
Sort_scan 0
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 1
Handler_read_key 0
Handler_read_last 0
Handler_read_next 4
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 0
Handler_read_rnd_deleted 0
Handler_read_rnd_next 0
FLUSH STATUS;
DELETE FROM t2 WHERE b = 10 ORDER BY a, c LIMIT 5;
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 0
Sort_range 0
Sort_rows 0
Sort_scan 0
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 1
Handler_read_key 0
Handler_read_last 0
Handler_read_next 4
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 0
Handler_read_rnd_deleted 0
Handler_read_rnd_next 0
## should be 5 (previous LIMIT)
SELECT 257 - COUNT(*) FROM t2 WHERE b = 10;
257 - COUNT(*)
5
DROP TABLE t2;
#
# as above + partial index, should use filesort
#
CREATE TABLE t2 (a CHAR(2), b CHAR(2), c CHAR(2), d CHAR(2), INDEX (a,b(1),c));
INSERT INTO t2 SELECT i, i, i, i FROM t1;
FLUSH STATUS;
SELECT * FROM t2 WHERE b = 10 ORDER BY a, c LIMIT 5;
a b c d
10 10 10 10
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 1
Sort_range 0
Sort_rows 1
Sort_scan 1
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 0
Handler_read_last 0
Handler_read_next 0
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 0
Handler_read_rnd_deleted 0
Handler_read_rnd_next 17
FLUSH STATUS;
DELETE FROM t2 WHERE b = 10 ORDER BY a, c LIMIT 5;
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 0
Sort_range 0
Sort_rows 1
Sort_scan 1
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 0
Handler_read_last 0
Handler_read_next 0
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 1
Handler_read_rnd_deleted 0
Handler_read_rnd_next 17
SELECT * FROM t2 WHERE b = 10 ORDER BY a, c;
a b c d
DROP TABLE t2;
#
# as above but index is without HA_READ_ORDER flag, should use filesort
#
CREATE TABLE t2 (a CHAR(2), b CHAR(2), c CHAR(2), d CHAR(2), INDEX (a,b,c)) ENGINE=HEAP;
INSERT INTO t2 SELECT i, i, i, i FROM t1;
FLUSH STATUS;
SELECT * FROM t2 WHERE b = 10 ORDER BY a, c LIMIT 5;
a b c d
10 10 10 10
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 1
Sort_range 0
Sort_rows 1
Sort_scan 1
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 0
Handler_read_last 0
Handler_read_next 0
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 1
Handler_read_rnd_deleted 0
Handler_read_rnd_next 17
FLUSH STATUS;
DELETE FROM t2 WHERE b = 10 ORDER BY a, c LIMIT 5;
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 0
Sort_range 0
Sort_rows 1
Sort_scan 1
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 0
Handler_read_last 0
Handler_read_next 0
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 1
Handler_read_rnd_deleted 0
Handler_read_rnd_next 17
SELECT * FROM t2 WHERE b = 10 ORDER BY a, c;
a b c d
DROP TABLE t2;
#
# quick select is Index Merge, should use filesort
#
CREATE TABLE t2 (i INT, key1 INT, key2 INT, INDEX (key1), INDEX (key2));
INSERT INTO t2 (key1, key2) SELECT i, i FROM t1;
FLUSH STATUS;
SELECT * FROM t2 WHERE key1 < 13 or key2 < 14 ORDER BY key1;
i key1 key2
NULL 10 10
NULL 11 11
NULL 12 12
NULL 13 13
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 0
Sort_range 1
Sort_rows 4
Sort_scan 0
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 2
Handler_read_last 0
Handler_read_next 7
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 4
Handler_read_rnd_deleted 0
Handler_read_rnd_next 0
EXPLAIN EXTENDED SELECT * FROM t2 WHERE key1 < 13 or key2 < 14 ORDER BY key1;
id select_type table type possible_keys key key_len ref rows filtered Extra
x x x x x x x x x x Using sort_union(key1,key2); Using where; Using filesort
Warnings:
x x x
FLUSH STATUS;
DELETE FROM t2 WHERE key1 < 13 or key2 < 14 ORDER BY key1;
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 0
Sort_range 1
Sort_rows 4
Sort_scan 0
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 2
Handler_read_last 0
Handler_read_next 7
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 8
Handler_read_rnd_deleted 0
Handler_read_rnd_next 0
SELECT * FROM t2 WHERE key1 < 13 or key2 < 14 ORDER BY key1;
i key1 key2
EXPLAIN EXTENDED SELECT * FROM t2 WHERE key1 < 13 or key2 < 14 ORDER BY key1;
id select_type table type possible_keys key key_len ref rows filtered Extra
x x x x x x x x x x Using sort_union(key1,key2); Using where; Using filesort
Warnings:
x x x
DROP TABLE t2;
#
# reverse quick select, should not use filesort
#
CREATE TABLE t2(a INT, i INT PRIMARY KEY);
INSERT INTO t2 (i) SELECT i FROM t1;
FLUSH STATUS;
SELECT * FROM t2 WHERE i > 10 AND i <= 18 ORDER BY i DESC LIMIT 5;
a i
NULL 18
NULL 17
NULL 16
NULL 15
NULL 14
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 0
Sort_range 0
Sort_rows 0
Sort_scan 0
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 1
Handler_read_last 0
Handler_read_next 0
Handler_read_prev 4
Handler_read_retry 0
Handler_read_rnd 0
Handler_read_rnd_deleted 0
Handler_read_rnd_next 0
FLUSH STATUS;
DELETE FROM t2 WHERE i > 10 AND i <= 18 ORDER BY i DESC LIMIT 5;
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 0
Sort_range 0
Sort_rows 0
Sort_scan 0
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 1
Handler_read_last 0
Handler_read_next 0
Handler_read_prev 4
Handler_read_retry 0
Handler_read_rnd 0
Handler_read_rnd_deleted 0
Handler_read_rnd_next 0
SELECT * FROM t2 WHERE i > 10 AND i <= 18 ORDER BY i;
a i
NULL 11
NULL 12
NULL 13
DROP TABLE t2;
#
# mixed sorting direction, should use filesort
#
CREATE TABLE t2 (a CHAR(2), b CHAR(2), c CHAR(2), INDEX (a, b));
INSERT INTO t2 SELECT i, i, i FROM t1;
FLUSH STATUS;
SELECT * FROM t2 ORDER BY a, b DESC LIMIT 5;
a b c
10 10 10
11 11 11
12 12 12
13 13 13
14 14 14
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 1
Sort_range 0
Sort_rows 5
Sort_scan 1
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 0
Handler_read_last 0
Handler_read_next 0
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 0
Handler_read_rnd_deleted 0
Handler_read_rnd_next 17
FLUSH STATUS;
DELETE FROM t2 ORDER BY a, b DESC LIMIT 5;
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 0
Sort_range 0
Sort_rows 16
Sort_scan 1
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 0
Handler_read_last 0
Handler_read_next 0
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 5
Handler_read_rnd_deleted 0
Handler_read_rnd_next 17
SELECT * FROM t2 ORDER BY a, b DESC;
a b c
15 15 15
16 16 16
17 17 17
18 18 18
19 19 19
20 20 20
21 21 21
22 22 22
23 23 23
24 24 24
25 25 25
DROP TABLE t2;
#
# LIMIT with no WHERE and DESC direction, should not use filesort
#
CREATE TABLE t2 (a CHAR(2), b CHAR(2), c CHAR(2), INDEX (a, b));
INSERT INTO t2 (a, b) SELECT i, i FROM t1;
INSERT INTO t2 (a, b) SELECT t1.i, t1.i FROM t1, t1 x1, t1 x2;
FLUSH STATUS;
SELECT * FROM t2 ORDER BY a, b LIMIT 5;
a b c
10 10 NULL
10 10 NULL
10 10 NULL
10 10 NULL
10 10 NULL
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 0
Sort_range 0
Sort_rows 0
Sort_scan 0
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 1
Handler_read_key 0
Handler_read_last 0
Handler_read_next 4
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 0
Handler_read_rnd_deleted 0
Handler_read_rnd_next 0
FLUSH STATUS;
SELECT * FROM t2 ORDER BY a DESC, b DESC LIMIT 5;
a b c
25 25 NULL
25 25 NULL
25 25 NULL
25 25 NULL
25 25 NULL
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 0
Sort_range 0
Sort_rows 0
Sort_scan 0
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 0
Handler_read_last 1
Handler_read_next 0
Handler_read_prev 4
Handler_read_retry 0
Handler_read_rnd 0
Handler_read_rnd_deleted 0
Handler_read_rnd_next 0
FLUSH STATUS;
DELETE FROM t2 ORDER BY a DESC, b DESC LIMIT 5;
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 0
Sort_range 0
Sort_rows 0
Sort_scan 0
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 0
Handler_read_last 1
Handler_read_next 0
Handler_read_prev 4
Handler_read_retry 0
Handler_read_rnd 0
Handler_read_rnd_deleted 0
Handler_read_rnd_next 0
SELECT * FROM t2 WHERE c = 10 ORDER BY a DESC, b DESC;
a b c
DROP TABLE t1, t2;
#
# Bug #36569: UPDATE ... WHERE ... ORDER BY... always does a filesort
# even if not required
#
CREATE TABLE t1 (i INT);
INSERT INTO t1 VALUES (10),(11),(12),(13),(14),(15),(16),(17),(18),(19),
(20),(21),(22),(23),(24),(25);
CREATE TABLE t2(a INT, i INT PRIMARY KEY);
INSERT INTO t2 (i) SELECT i FROM t1;
FLUSH STATUS;
SELECT * FROM t2 WHERE i > 10 AND i <= 18 ORDER BY i LIMIT 5;
a i
NULL 11
NULL 12
NULL 13
NULL 14
NULL 15
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 0
Sort_range 0
Sort_rows 0
Sort_scan 0
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 1
Handler_read_last 0
Handler_read_next 4
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 0
Handler_read_rnd_deleted 0
Handler_read_rnd_next 0
FLUSH STATUS;
UPDATE t2 SET a = 10 WHERE i > 10 AND i <= 18 ORDER BY i LIMIT 5;
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 0
Sort_range 0
Sort_rows 0
Sort_scan 0
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 1
Handler_read_last 0
Handler_read_next 4
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 5
Handler_read_rnd_deleted 0
Handler_read_rnd_next 0
SELECT * FROM t2 WHERE i > 10 AND i <= 18 ORDER BY i;
a i
10 11
10 12
10 13
10 14
10 15
NULL 16
NULL 17
NULL 18
DROP TABLE t2;
#
# index on field prefix:
#
CREATE TABLE t2(a INT, i CHAR(2), INDEX(i(1)));
INSERT INTO t2 (i) SELECT i FROM t1;
FLUSH STATUS;
SELECT * FROM t2 WHERE i > 10 AND i <= 18 ORDER BY i LIMIT 5;
a i
NULL 11
NULL 12
NULL 13
NULL 14
NULL 15
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 1
Sort_range 0
Sort_rows 5
Sort_scan 1
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 0
Handler_read_last 0
Handler_read_next 0
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 0
Handler_read_rnd_deleted 0
Handler_read_rnd_next 17
FLUSH STATUS;
UPDATE t2 SET a = 10 WHERE i > 10 AND i <= 18 ORDER BY i LIMIT 5;
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 1
Sort_range 0
Sort_rows 5
Sort_scan 1
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 0
Handler_read_last 0
Handler_read_next 0
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 5
Handler_read_rnd_deleted 0
Handler_read_rnd_next 17
SELECT * FROM t2 WHERE i > 10 AND i <= 18 ORDER BY i;
a i
10 11
10 12
10 13
10 14
10 15
NULL 16
NULL 17
NULL 18
DROP TABLE t2;
#
# constant inside ORDER BY list, should use filesort
# on a small table
#
CREATE TABLE t2(a INT, b INT, c INT, d INT, INDEX(a, b, c));
INSERT INTO t2 (a, b, c) SELECT i, i, i FROM t1;
FLUSH STATUS;
SELECT * FROM t2 WHERE b = 10 ORDER BY a, c LIMIT 5;
a b c d
10 10 10 NULL
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 1
Sort_range 0
Sort_rows 1
Sort_scan 1
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 0
Handler_read_last 0
Handler_read_next 0
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 0
Handler_read_rnd_deleted 0
Handler_read_rnd_next 17
FLUSH STATUS;
UPDATE t2 SET d = 10 WHERE b = 10 ORDER BY a, c LIMIT 5;
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 1
Sort_range 0
Sort_rows 1
Sort_scan 1
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 0
Handler_read_last 0
Handler_read_next 0
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 1
Handler_read_rnd_deleted 0
Handler_read_rnd_next 17
## should be 5 (previous LIMIT)
SELECT COUNT(*) FROM t2 WHERE b = 10 AND d = 10 ORDER BY a, c;
COUNT(*)
1
DROP TABLE t2;
#
# same test as above (constant inside ORDER BY list), but with
# a larger table - should not use filesort
#
CREATE TABLE t2(a INT, b INT, c INT, d INT, INDEX(a, b, c));
INSERT INTO t2 (a, b, c) SELECT i, i, i FROM t1;
INSERT INTO t2 (a, b, c) SELECT t1.i, t1.i, t1.i FROM t1, t1 x1, t1 x2;
FLUSH STATUS;
SELECT * FROM t2 WHERE b = 10 ORDER BY a, c LIMIT 5;
a b c d
10 10 10 NULL
10 10 10 NULL
10 10 10 NULL
10 10 10 NULL
10 10 10 NULL
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 0
Sort_range 0
Sort_rows 0
Sort_scan 0
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 1
Handler_read_key 0
Handler_read_last 0
Handler_read_next 4
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 0
Handler_read_rnd_deleted 0
Handler_read_rnd_next 0
FLUSH STATUS;
UPDATE t2 SET d = 10 WHERE b = 10 ORDER BY a, c LIMIT 5;
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 0
Sort_range 0
Sort_rows 0
Sort_scan 0
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 1
Handler_read_key 0
Handler_read_last 0
Handler_read_next 4
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 5
Handler_read_rnd_deleted 0
Handler_read_rnd_next 0
## should be 5 (previous LIMIT)
SELECT COUNT(*) FROM t2 WHERE b = 10 AND d = 10 ORDER BY a, c;
COUNT(*)
5
DROP TABLE t2;
#
# as above + partial index, should use filesort
#
CREATE TABLE t2 (a CHAR(2), b CHAR(2), c CHAR(2), d CHAR(2), INDEX (a,b(1),c));
INSERT INTO t2 SELECT i, i, i, i FROM t1;
FLUSH STATUS;
SELECT * FROM t2 WHERE b = 10 ORDER BY a, c LIMIT 5;
a b c d
10 10 10 10
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 1
Sort_range 0
Sort_rows 1
Sort_scan 1
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 0
Handler_read_last 0
Handler_read_next 0
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 0
Handler_read_rnd_deleted 0
Handler_read_rnd_next 17
FLUSH STATUS;
UPDATE t2 SET d = 10 WHERE b = 10 ORDER BY a, c LIMIT 5;
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 1
Sort_range 0
Sort_rows 1
Sort_scan 1
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 0
Handler_read_last 0
Handler_read_next 0
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 1
Handler_read_rnd_deleted 0
Handler_read_rnd_next 17
SELECT * FROM t2 WHERE b = 10 ORDER BY a, c;
a b c d
10 10 10 10
DROP TABLE t2;
#
# as above but index is without HA_READ_ORDER flag, should use filesort
#
CREATE TABLE t2 (a CHAR(2), b CHAR(2), c CHAR(2), d CHAR(2), INDEX (a,b,c)) ENGINE=HEAP;
INSERT INTO t2 SELECT i, i, i, i FROM t1;
FLUSH STATUS;
SELECT * FROM t2 WHERE b = 10 ORDER BY a, c LIMIT 5;
a b c d
10 10 10 10
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 1
Sort_range 0
Sort_rows 1
Sort_scan 1
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 0
Handler_read_last 0
Handler_read_next 0
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 1
Handler_read_rnd_deleted 0
Handler_read_rnd_next 17
FLUSH STATUS;
UPDATE t2 SET d = 10 WHERE b = 10 ORDER BY a, c LIMIT 5;
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 1
Sort_range 0
Sort_rows 1
Sort_scan 1
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 0
Handler_read_last 0
Handler_read_next 0
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 1
Handler_read_rnd_deleted 0
Handler_read_rnd_next 17
SELECT * FROM t2 WHERE b = 10 ORDER BY a, c;
a b c d
10 10 10 10
DROP TABLE t2;
#
# quick select is Index Merge, should use filesort
#
CREATE TABLE t2 (i INT, key1 INT, key2 INT, INDEX (key1), INDEX (key2));
INSERT INTO t2 (key1, key2) SELECT i, i FROM t1;
FLUSH STATUS;
SELECT * FROM t2 WHERE key1 < 13 or key2 < 14 ORDER BY key1;
i key1 key2
NULL 10 10
NULL 11 11
NULL 12 12
NULL 13 13
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 0
Sort_range 1
Sort_rows 4
Sort_scan 0
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 2
Handler_read_last 0
Handler_read_next 7
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 4
Handler_read_rnd_deleted 0
Handler_read_rnd_next 0
EXPLAIN EXTENDED SELECT * FROM t2 WHERE key1 < 13 or key2 < 14 ORDER BY key1;
id select_type table type possible_keys key key_len ref rows filtered Extra
x x x x x x x x x x Using sort_union(key1,key2); Using where; Using filesort
Warnings:
x x x
FLUSH STATUS;
UPDATE t2 SET i = 123 WHERE key1 < 13 or key2 < 14 ORDER BY key1;
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 0
Sort_range 1
Sort_rows 4
Sort_scan 0
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 2
Handler_read_last 0
Handler_read_next 7
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 8
Handler_read_rnd_deleted 0
Handler_read_rnd_next 0
SELECT * FROM t2 WHERE key1 < 13 or key2 < 14 ORDER BY key1;
i key1 key2
123 10 10
123 11 11
123 12 12
123 13 13
EXPLAIN EXTENDED SELECT * FROM t2 WHERE key1 < 13 or key2 < 14 ORDER BY key1;
id select_type table type possible_keys key key_len ref rows filtered Extra
x x x x x x x x x x Using sort_union(key1,key2); Using where; Using filesort
Warnings:
x x x
DROP TABLE t2;
#
# reverse quick select, should not use filesort
#
CREATE TABLE t2(a INT, i INT PRIMARY KEY);
INSERT INTO t2 (i) SELECT i FROM t1;
FLUSH STATUS;
SELECT * FROM t2 WHERE i > 10 AND i <= 18 ORDER BY i DESC LIMIT 5;
a i
NULL 18
NULL 17
NULL 16
NULL 15
NULL 14
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 0
Sort_range 0
Sort_rows 0
Sort_scan 0
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 1
Handler_read_last 0
Handler_read_next 0
Handler_read_prev 4
Handler_read_retry 0
Handler_read_rnd 0
Handler_read_rnd_deleted 0
Handler_read_rnd_next 0
FLUSH STATUS;
UPDATE t2 SET a = 10 WHERE i > 10 AND i <= 18 ORDER BY i DESC LIMIT 5;
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 0
Sort_range 0
Sort_rows 0
Sort_scan 0
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 1
Handler_read_last 0
Handler_read_next 0
Handler_read_prev 4
Handler_read_retry 0
Handler_read_rnd 5
Handler_read_rnd_deleted 0
Handler_read_rnd_next 0
SELECT * FROM t2 WHERE i > 10 AND i <= 18 ORDER BY i;
a i
NULL 11
NULL 12
NULL 13
10 14
10 15
10 16
10 17
10 18
DROP TABLE t2;
#
# mixed sorting direction, should use filesort
#
CREATE TABLE t2 (a CHAR(2), b CHAR(2), c CHAR(2), INDEX (a, b));
INSERT INTO t2 SELECT i, i, i FROM t1;
FLUSH STATUS;
SELECT * FROM t2 ORDER BY a, b DESC LIMIT 5;
a b c
10 10 10
11 11 11
12 12 12
13 13 13
14 14 14
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 1
Sort_range 0
Sort_rows 5
Sort_scan 1
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 0
Handler_read_last 0
Handler_read_next 0
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 0
Handler_read_rnd_deleted 0
Handler_read_rnd_next 17
FLUSH STATUS;
UPDATE t2 SET c = 10 ORDER BY a, b DESC LIMIT 5;
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 1
Sort_range 0
Sort_rows 5
Sort_scan 1
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 0
Handler_read_last 0
Handler_read_next 0
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 5
Handler_read_rnd_deleted 0
Handler_read_rnd_next 17
SELECT * FROM t2 WHERE c = 10 ORDER BY a, b DESC;
a b c
10 10 10
11 11 10
12 12 10
13 13 10
14 14 10
DROP TABLE t2;
#
# LIMIT with no WHERE and DESC direction, should not use filesort
#
CREATE TABLE t2 (a CHAR(2), b CHAR(2), c CHAR(2), INDEX (a, b));
INSERT INTO t2 (a, b) SELECT i, i FROM t1;
INSERT INTO t2 (a, b) SELECT t1.i, t1.i FROM t1, t1 x1, t1 x2;
FLUSH STATUS;
SELECT * FROM t2 ORDER BY a, b LIMIT 5;
a b c
10 10 NULL
10 10 NULL
10 10 NULL
10 10 NULL
10 10 NULL
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 0
Sort_range 0
Sort_rows 0
Sort_scan 0
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 1
Handler_read_key 0
Handler_read_last 0
Handler_read_next 4
Handler_read_prev 0
Handler_read_retry 0
Handler_read_rnd 0
Handler_read_rnd_deleted 0
Handler_read_rnd_next 0
FLUSH STATUS;
SELECT * FROM t2 ORDER BY a DESC, b DESC LIMIT 5;
a b c
25 25 NULL
25 25 NULL
25 25 NULL
25 25 NULL
25 25 NULL
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 0
Sort_range 0
Sort_rows 0
Sort_scan 0
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 0
Handler_read_last 1
Handler_read_next 0
Handler_read_prev 4
Handler_read_retry 0
Handler_read_rnd 0
Handler_read_rnd_deleted 0
Handler_read_rnd_next 0
FLUSH STATUS;
UPDATE t2 SET c = 10 ORDER BY a DESC, b DESC LIMIT 5;
SHOW SESSION STATUS LIKE 'Sort%';
Variable_name Value
Sort_merge_passes 0
Sort_priority_queue_sorts 0
Sort_range 0
Sort_rows 0
Sort_scan 0
SHOW STATUS LIKE 'Handler_read_%';
Variable_name Value
Handler_read_first 0
Handler_read_key 0
Handler_read_last 1
Handler_read_next 0
Handler_read_prev 4
Handler_read_retry 0
Handler_read_rnd 5
Handler_read_rnd_deleted 0
Handler_read_rnd_next 0
SELECT * FROM t2 WHERE c = 10 ORDER BY a DESC, b DESC;
a b c
25 25 10
25 25 10
25 25 10
25 25 10
25 25 10
DROP TABLE t1, t2;
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