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
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
|
#
# Check null keys
# test needs MyISAM storage engine
--source include/force_myisam_default.inc
--source include/have_myisam.inc
SET sql_mode = 'NO_ENGINE_SUBSTITUTION';
create table t1 (a int, b int not null,unique key (a,b),index(b)) engine=myisam;
insert ignore into t1 values (1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(null,7),(9,9),(8,8),(7,7),(null,9),(null,9),(6,6);
explain select * from t1 where a is null;
explain select * from t1 where a is null and b = 2;
explain select * from t1 where a is null and b = 7;
explain select * from t1 where a=2 and b = 2;
explain select * from t1 where a<=>b limit 2;
explain select * from t1 where (a is null or a > 0 and a < 3) and b < 5 limit 3;
--skip_if_hypergraph # Depends on the query plan.
explain format=tree select * from t1 where (a is null or a = 7) and b=7;
explain select * from t1 where (a is null or a = 7) and b=7;
explain select * from t1 where (a is null or a = 7) and b=7 order by a;
explain select * from t1 where (a is null and b>a) or a is null and b=7 limit 2;
explain select * from t1 where a is null and b=9 or a is null and b=7 limit 3;
explain select * from t1 where a > 1 and a < 3 limit 1;
explain select * from t1 where a > 8 and a < 9;
--sorted_result
select * from t1 where a is null;
--sorted_result
select * from t1 where a is null and b = 7;
--sorted_result
select * from t1 where a<=>b limit 2;
--sorted_result
select * from t1 where (a is null or a > 0 and a < 3) and b < 5 limit 3;
--sorted_result
select * from t1 where (a is null or a > 0 and a < 3) and b > 7 limit 3;
--sorted_result
select * from t1 where (a is null or a = 7) and b=7;
--sorted_result
select * from t1 where a is null and b=9 or a is null and b=7 limit 3;
--sorted_result
select * from t1 where a > 1 and a < 3 limit 1;
--sorted_result
select * from t1 where a > 8 and a < 9;
create table t2 like t1;
insert into t2 select * from t1;
alter table t1 modify b blob not null, add c int not null, drop key a, add unique key (a,b(20),c), drop key b, add key (b(10));
explain select * from t1 where a is null and b = 2;
explain select * from t1 where a is null and b = 2 and c=0;
explain select * from t1 where a is null and b = 7 and c=0;
explain select * from t1 where a=2 and b = 2;
explain select * from t1 where a<=>b limit 2;
explain select * from t1 where (a is null or a > 0 and a < 3) and b < 5 and c=0 limit 3;
explain select * from t1 where (a is null or a = 7) and b=7 and c=0;
explain select * from t1 where (a is null and b>a) or a is null and b=7 limit 2;
explain select * from t1 where a is null and b=9 or a is null and b=7 limit 3;
explain select * from t1 where a > 1 and a < 3 limit 1;
explain select * from t1 where a is null and b=7 or a > 1 and a < 3 limit 1;
explain select * from t1 where a > 8 and a < 9;
explain select * from t1 where b like "6%";
--sorted_result
select * from t1 where a is null;
--sorted_result
select * from t1 where a is null and b = 7 and c=0;
--sorted_result
select * from t1 where a<=>b limit 2;
--sorted_result
select * from t1 where (a is null or a > 0 and a < 3) and b < 5 limit 3;
--sorted_result
select * from t1 where (a is null or a > 0 and a < 3) and b > 7 limit 3;
--sorted_result
select * from t1 where (a is null or a = 7) and b=7 and c=0;
--sorted_result
select * from t1 where a is null and b=9 or a is null and b=7 limit 3;
--sorted_result
select * from t1 where b like "6%";
#
# Test ref_or_null optimization
#
drop table t1;
rename table t2 to t1;
alter table t1 modify b int null;
insert into t1 values (7,null), (8,null), (8,7);
explain select * from t1 where a = 7 and (b=7 or b is null);
--sorted_result
select * from t1 where a = 7 and (b=7 or b is null);
explain select * from t1 where (a = 7 or a is null) and (b=7 or b is null);
--sorted_result
select * from t1 where (a = 7 or a is null) and (b=7 or b is null);
explain select * from t1 where (a = 7 or a is null) and (a = 7 or a is null);
--sorted_result
select * from t1 where (a = 7 or a is null) and (a = 7 or a is null);
create table t2 (a int);
insert into t2 values (7),(8);
explain select * from t2 straight_join t1 where t1.a=t2.a and b is null;
drop index b on t1;
explain select * from t2,t1 where t1.a=t2.a and b is null;
--sorted_result
select * from t2,t1 where t1.a=t2.a and b is null;
explain select * from t2,t1 where t1.a=t2.a and (b= 7 or b is null);
--sorted_result
select * from t2,t1 where t1.a=t2.a and (b= 7 or b is null);
explain select * from t2,t1 where (t1.a=t2.a or t1.a is null) and b= 7;
--sorted_result
select * from t2,t1 where (t1.a=t2.a or t1.a is null) and b= 7;
explain select * from t2,t1 where (t1.a=t2.a or t1.a is null) and (b= 7 or b is null);
--sorted_result
select * from t2,t1 where (t1.a=t2.a or t1.a is null) and (b= 7 or b is null);
insert into t2 values (null),(6);
delete from t1 where a=8;
explain select * from t2,t1 where t1.a=t2.a or t1.a is null;
explain select * from t2,t1 where t1.a<=>t2.a or (t1.a is null and t1.b <> 9);
--sorted_result
select * from t2,t1 where t1.a<=>t2.a or (t1.a is null and t1.b <> 9);
drop table t1,t2;
#
# The following failed for Matt Loschert
#
CREATE TABLE t1 (
id int(10) unsigned NOT NULL auto_increment,
uniq_id int(10) unsigned default NULL,
PRIMARY KEY (id),
UNIQUE KEY idx1 (uniq_id)
) ENGINE=MyISAM;
CREATE TABLE t2 (
id int(10) unsigned NOT NULL auto_increment,
uniq_id int(10) unsigned default NULL,
PRIMARY KEY (id)
) ENGINE=MyISAM;
INSERT INTO t1 VALUES (1,NULL),(2,NULL),(3,1),(4,2),(5,NULL),(6,NULL),(7,3),(8,4),(9,NULL),(10,NULL);
INSERT INTO t2 VALUES (1,NULL),(2,NULL),(3,1),(4,2),(5,NULL),(6,NULL),(7,3),(8,4),(9,NULL),(10,NULL);
#
# Check IS NULL optimization
#
explain select id from t1 where uniq_id is null;
explain select id from t1 where uniq_id =1;
#
# Check updates
#
UPDATE t1 SET id=id+100 where uniq_id is null;
UPDATE t2 SET id=id+100 where uniq_id is null;
select id from t1 where uniq_id is null;
select id from t2 where uniq_id is null;
#
# Delete all records from each table where the uniq_id field is null
#
DELETE FROM t1 WHERE uniq_id IS NULL;
DELETE FROM t2 WHERE uniq_id IS NULL;
#
# Select what is left -- notice the difference
#
SELECT * FROM t1 ORDER BY uniq_id, id;
SELECT * FROM t2 ORDER BY uniq_id, id;
DROP table t1,t2;
#
# This crashed MySQL 3.23.47
#
CREATE TABLE `t1` (
`order_id` char(32) NOT NULL default '',
`product_id` char(32) NOT NULL default '',
`product_type` int(11) NOT NULL default '0',
PRIMARY KEY (`order_id`,`product_id`,`product_type`)
) ENGINE=MyISAM;
CREATE TABLE `t2` (
`order_id` char(32) NOT NULL default '',
`product_id` char(32) NOT NULL default '',
`product_type` int(11) NOT NULL default '0',
PRIMARY KEY (`order_id`,`product_id`,`product_type`)
) ENGINE=MyISAM;
INSERT INTO t1 (order_id, product_id, product_type) VALUES
('3d7ce39b5d4b3e3d22aaafe9b633de51',1206029, 3),
('3d7ce39b5d4b3e3d22aaafe9b633de51',5880836, 3),
('9d9aad7764b5b2c53004348ef8d34500',2315652, 3);
INSERT INTO t2 (order_id, product_id, product_type) VALUES
('9d9aad7764b5b2c53004348ef8d34500',2315652, 3);
select t1.* from t1
left join t2 using(order_id, product_id, product_type)
where t2.order_id=NULL;
select t1.* from t1
left join t2 using(order_id, product_id, product_type)
where t2.order_id is NULL;
drop table t1,t2;
SET sql_mode = default;
#
# Test that EXPLAIN format=tree prints "or NULL" on the keypart that
# is actually nullable, not always the first one.
#
create table t1 (a int, b int not null,unique key (b,a),index(b));
insert ignore into t1 values (1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(null,7),(9,9),(8,8),(7,7),(null,9),(null,9),(6,6);
--skip_if_hypergraph # Depends on the query plan.
explain format=tree select * from t1 where (a is null or a = 7) and b=7;
drop table t1;
|
