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
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
|
#
# MariaDB tests for EXPLAIN UPDATE/DELETE.
#
--source include/have_partition.inc
--disable_warnings
drop table if exists t0, t1;
--enable_warnings
create table t0 (a int) engine=myisam;
insert into t0 values (1),(2),(3),(4),(5),(6),(7),(8);
--echo #
--echo # Tests for single-table DELETE
--echo #
explain select * from t0 where a=3;
explain delete from t0 where a=3;
--echo # DELETE without WHERE is a special case:
explain delete from t0;
create table t1 (a int, b int, filler char(100), key(a), key(b));
insert into t1
select A.a+10*B.a + 10*C.a, A.a+10*B.a + 10*C.a, 'filler'
from t0 A, t0 B, t0 C;
--echo # This should use an index, possible_keys=NULL because there is no WHERE
explain delete from t1 order by a limit 2;
--echo # This should use range, possible_keys={a,b}
explain delete from t1 where a<20 and b < 10;
--echo # This should use ALL + filesort
explain delete from t1 order by a+1 limit 2;
--echo # This should use range + using filesort
explain delete from t1 where a<20 order by b limit 2;
--echo # Try some subqueries:
explain delete from t1 where a < (select max(a) from t0);
explain delete from t1 where a < (select max(a) from t0 where a < t1.b);
--echo #
--echo # Tests for multi-table DELETE
--echo #
explain delete t1 from t0, t1 where t0.a = t1.a;
drop table t0, t1;
--echo # ###################################################################
--echo # ## EXPLAIN UPDATE tests
--echo # ###################################################################
create table t0 (a int) engine=myisam;
insert into t0 values (1),(2),(3),(4),(5),(6),(7),(8);
explain update t0 set a=3 where a=4;
create table t1 (a int, b int, filler char(100), key(a), key(b));
insert into t1
select A.a+10*B.a + 10*C.a, A.a+10*B.a + 10*C.a, 'filler'
from t0 A, t0 B, t0 C;
explain update t1 set a=a+1 where 3>4;
explain update t1 set a=a+1 where a=3 and a=4;
--echo # This should use an index, possible_keys=NULL because there is no WHERE
explain update t1 set a=a+1 order by a limit 2;
--echo # This should use range, possible_keys={a,b}
explain update t1 set filler='fooo' where a<20 and b < 10;
--echo # This should use ALL + filesort
explain update t1 set filler='fooo' order by a+1 limit 2;
--echo # This should use range + using filesort
explain update t1 set filler='fooo' where a<20 order by b limit 2;
--echo # Try some subqueries:
explain update t1 set filler='fooo' where a < (select max(a) from t0);
explain update t1 set filler='fooo' where a < (select max(a) from t0 where a < t1.b);
--echo #
--echo # Tests for multi-table UPDATE
--echo #
explain update t0, t1 set t1.a=t1.a+1 where t0.a = t1.a;
drop table t0, t1;
--echo #
--echo # Try DELETE ... RETURNING ...
--echo #
create table t0 (a int);
insert into t0 values (1),(2),(3),(4);
explain delete from t0 where a=1 returning a;
explain delete from t0 returning a;
drop table t0;
--echo #
--echo # MDEV-5070 - EXPLAIN INSERT ... SELECT crashes on 10.0-base-explain-slowquerylog
--echo #
create table t0 (a int);
insert into t0 values (1),(2),(3),(4),(5),(6),(7),(8);
create table t1 (a int);
explain insert into t1 select * from t0;
explain replace into t1 select * from t0;
drop table t0, t1;
--echo #
--echo # MDEV-5067: Valgrind warnings (Invalid read) in QPF_table_access::print_explain
--echo #
CREATE TABLE t1 (i INT) ENGINE=MyISAM;
INSERT INTO t1 VALUES (7),(0),(9);
SELECT * FROM t1 INNER JOIN ( SELECT DISTINCT * FROM t1 ) AS sq ON (sq.i = t1.i);
DROP TABLE t1;
--echo #
--echo # MDEV-5093, MDEV-5094: EXPLAIN PARTITIONS and EXPLAIN EXTENDED do not
--echo # work for EXPLAIN UPDATE.
--echo #
create table t1 (i int);
explain partitions update t1 set i = 3;
create table t2 (a int, b int) partition by hash(a) partitions 5;
insert into t2 values (0,0),(1,1),(2,2),(3,3),(4,4);
explain partitions update t2 set b=3 where a in (3,4);
explain partitions delete from t2 where a in (3,4);
explain extended update t2 set b=3 where a in (3,4);
explain extended delete from t2 where a in (3,4);
drop table t1,t2;
--echo #
--echo # Check the special case where partition pruning removed all partitions
--echo #
create table t1 (a int, b int)
partition by range (a) (
partition p0 values less than (10),
partition p1 values less than (20),
partition p2 values less than (30)
);
insert into t1 values (9,9), (19,19), (29,29);
explain partitions select * from t1 where a in (32,33);
explain partitions delete from t1 where a in (32,33);
explain partitions update t1 set b=12345 where a in (32,33);
drop table t1;
|
