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
158
159
160
161
162
163
164
165
166
|
--echo #
--echo # MDEV-27576 Use DESC indexes for MIN/MAX optimization
--echo #
--source include/have_sequence.inc
--source include/have_innodb.inc
create or replace table t1 (a int, key(a desc)) engine=innodb;
insert into t1 select seq * 2 from seq_1_to_100 order by rand(1);
let $query=
select max(a) from t1;
eval explain $query;
eval $query;
let $query=
select min(a) from t1;
eval explain $query;
eval $query;
let $query=
select max(a) from t1 where a < 100;
eval explain $query;
eval $query;
let $query=
select min(a) from t1 where a > 100;
eval explain $query;
eval $query;
let $query=
select max(a) from t1 where a <= 100;
eval explain $query;
eval $query;
let $query=
select min(a) from t1 where a >= 100;
eval explain $query;
eval $query;
let $query=
select max(a) from t1 where a <= 99;
eval explain $query;
eval $query;
let $query=
select min(a) from t1 where a >= 99;
eval explain $query;
eval $query;
# the other side
let $query=
select max(a) from t1 where a > 100;
eval explain $query;
eval $query;
let $query=
select max(a) from t1 where a > 1000;
eval explain $query;
eval $query;
let $query=
select min(a) from t1 where a < 100;
eval explain $query;
eval $query;
let $query=
select min(a) from t1 where a < 0;
eval explain $query;
eval $query;
let $query=
select max(a) from t1 where a >= 100;
eval explain $query;
eval $query;
let $query=
select max(a) from t1 where a >= 1000;
eval explain $query;
eval $query;
let $query=
select min(a) from t1 where a <= 100;
eval explain $query;
eval $query;
let $query=
select min(a) from t1 where a <= 0;
eval explain $query;
eval $query;
let $query=
select max(a) from t1 where a >= 99;
eval explain $query;
eval $query;
let $query=
select min(a) from t1 where a <= 99;
eval explain $query;
eval $query;
# double reversion
let $query=
select max(200 - a) from t1;
replace_column 9 #;
eval explain $query;
eval $query;
let $query=
select min(200 - a) from t1;
replace_column 9 #;
eval explain $query;
eval $query;
# more complex key situations
create or replace table t1 (a int, b int, key(a desc, b asc)) engine=innodb;
insert into t1 select seq * 2, seq * 2 from seq_1_to_100 order by rand(1);
let $query=
select max(a) from t1;
eval explain $query;
eval $query;
let $query=
select min(a) from t1;
eval explain $query;
eval $query;
create or replace table t1 (a int, b int, key(a asc), key (b desc)) engine=innodb;
insert into t1 select seq * 2, seq * 2 from seq_1_to_100 order by rand(1);
let $query=
select max(b) from t1;
eval explain $query;
eval $query;
let $query=
select min(b) from t1;
eval explain $query;
eval $query;
create or replace table t1 (a int, b int, key (b desc)) engine=innodb;
insert into t1 select seq * 2, seq * 2 from seq_1_to_100 order by rand(1);
let $query=
select max(b) from t1;
eval explain $query;
eval $query;
let $query=
select min(b) from t1;
eval explain $query;
eval $query;
# float example in the comment
CREATE OR REPLACE TABLE t1 (a FLOAT, KEY (a DESC));
INSERT INTO t1 VALUES (0.1234),(0.6789);
let $query=
SELECT MAX(a) FROM t1 WHERE a <= 0.6789;
eval explain $query;
eval $query;
# Cleanup
drop table t1;
--echo # end of test 11.4
|
