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
|
set global innodb_stats_method = default;
select @@innodb_stats_method;
@@innodb_stats_method
nulls_equal
select count(*) from bug30243_3 where org_id is not NULL;
count(*)
20
select count(*) from bug30243_3 where org_id is NULL;
count(*)
16384
select count(*) from bug30243_2 where org_id is not NULL;
count(*)
224
select count(*) from bug30243_2 where org_id is NULL;
count(*)
65536
select @@innodb_stats_method;
@@innodb_stats_method
nulls_equal
analyze table bug30243_1;
Table Op Msg_type Msg_text
test.bug30243_1 analyze status Engine-independent statistics collected
test.bug30243_1 analyze status OK
analyze table bug30243_2;
Table Op Msg_type Msg_text
test.bug30243_2 analyze status Engine-independent statistics collected
test.bug30243_2 analyze status OK
analyze table bug30243_3;
Table Op Msg_type Msg_text
test.bug30243_3 analyze status Engine-independent statistics collected
test.bug30243_3 analyze status OK
set global innodb_stats_method = "NULL";
ERROR 42000: Variable 'innodb_stats_method' can't be set to the value of 'NULL'
set global innodb_stats_method = "nulls_ignored";
select @@innodb_stats_method;
@@innodb_stats_method
nulls_ignored
analyze table bug30243_1;
Table Op Msg_type Msg_text
test.bug30243_1 analyze status Engine-independent statistics collected
test.bug30243_1 analyze status OK
analyze table bug30243_2;
Table Op Msg_type Msg_text
test.bug30243_2 analyze status Engine-independent statistics collected
test.bug30243_2 analyze status OK
analyze table bug30243_3;
Table Op Msg_type Msg_text
test.bug30243_3 analyze status Engine-independent statistics collected
test.bug30243_3 analyze status OK
explain SELECT COUNT(*), 0
FROM bug30243_1 orgs
LEFT JOIN bug30243_3 sa_opportunities
ON orgs.org_id=sa_opportunities.org_id
LEFT JOIN bug30243_2 contacts
ON orgs.org_id=contacts.org_id ;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE orgs ALL NULL NULL NULL NULL ROWS
1 SIMPLE sa_opportunities ref org_id org_id 5 test.orgs.org_id ROWS Using index
1 SIMPLE contacts ref contacts$org_id contacts$org_id 5 test.orgs.org_id ROWS Using index
select @@innodb_stats_method;
@@innodb_stats_method
nulls_ignored
set global innodb_stats_method = "nulls_unequal";
select @@innodb_stats_method;
@@innodb_stats_method
nulls_unequal
analyze table bug30243_1;
Table Op Msg_type Msg_text
test.bug30243_1 analyze status Engine-independent statistics collected
test.bug30243_1 analyze status OK
analyze table bug30243_2;
Table Op Msg_type Msg_text
test.bug30243_2 analyze status Engine-independent statistics collected
test.bug30243_2 analyze status OK
analyze table bug30243_3;
Table Op Msg_type Msg_text
test.bug30243_3 analyze status Engine-independent statistics collected
test.bug30243_3 analyze status OK
explain SELECT COUNT(*), 0
FROM bug30243_1 orgs
LEFT JOIN bug30243_3 sa_opportunities
ON orgs.org_id=sa_opportunities.org_id
LEFT JOIN bug30243_2 contacts
ON orgs.org_id=contacts.org_id;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE orgs ALL NULL NULL NULL NULL ROWS
1 SIMPLE sa_opportunities ref org_id org_id 5 test.orgs.org_id ROWS Using index
1 SIMPLE contacts ref contacts$org_id contacts$org_id 5 test.orgs.org_id ROWS Using index
SELECT COUNT(*) FROM table_bug30423 WHERE org_id IS NULL;
COUNT(*)
1024
set global innodb_stats_method = "nulls_unequal";
analyze table table_bug30423;
Table Op Msg_type Msg_text
test.table_bug30423 analyze status Engine-independent statistics collected
test.table_bug30423 analyze status OK
set global innodb_stats_method = "nulls_ignored";
analyze table table_bug30423;
Table Op Msg_type Msg_text
test.table_bug30423 analyze status Engine-independent statistics collected
test.table_bug30423 analyze status OK
set global innodb_stats_method = nulls_equal;
drop table bug30243_2;
drop table bug30243_1;
drop table bug30243_3;
drop table table_bug30423;
|
