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
|
--
-- ADVISORY LOCKS
--
BEGIN;
SELECT
pg_advisory_xact_lock(1), pg_advisory_xact_lock_shared(2),
pg_advisory_xact_lock(1, 1), pg_advisory_xact_lock_shared(2, 2);
SELECT locktype, classid, objid, objsubid, mode, granted
FROM pg_locks WHERE locktype = 'advisory'
ORDER BY classid, objid, objsubid;
-- pg_advisory_unlock_all() shouldn't release xact locks
SELECT pg_advisory_unlock_all();
SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
-- can't unlock xact locks
SELECT
pg_advisory_unlock(1), pg_advisory_unlock_shared(2),
pg_advisory_unlock(1, 1), pg_advisory_unlock_shared(2, 2);
-- automatically release xact locks at commit
COMMIT;
SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
BEGIN;
-- holding both session and xact locks on the same objects, xact first
SELECT
pg_advisory_xact_lock(1), pg_advisory_xact_lock_shared(2),
pg_advisory_xact_lock(1, 1), pg_advisory_xact_lock_shared(2, 2);
SELECT locktype, classid, objid, objsubid, mode, granted
FROM pg_locks WHERE locktype = 'advisory'
ORDER BY classid, objid, objsubid;
SELECT
pg_advisory_lock(1), pg_advisory_lock_shared(2),
pg_advisory_lock(1, 1), pg_advisory_lock_shared(2, 2);
ROLLBACK;
SELECT locktype, classid, objid, objsubid, mode, granted
FROM pg_locks WHERE locktype = 'advisory'
ORDER BY classid, objid, objsubid;
-- unlocking session locks
SELECT
pg_advisory_unlock(1), pg_advisory_unlock(1),
pg_advisory_unlock_shared(2), pg_advisory_unlock_shared(2),
pg_advisory_unlock(1, 1), pg_advisory_unlock(1, 1),
pg_advisory_unlock_shared(2, 2), pg_advisory_unlock_shared(2, 2);
SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
BEGIN;
-- holding both session and xact locks on the same objects, session first
SELECT
pg_advisory_lock(1), pg_advisory_lock_shared(2),
pg_advisory_lock(1, 1), pg_advisory_lock_shared(2, 2);
SELECT locktype, classid, objid, objsubid, mode, granted
FROM pg_locks WHERE locktype = 'advisory'
ORDER BY classid, objid, objsubid;
SELECT
pg_advisory_xact_lock(1), pg_advisory_xact_lock_shared(2),
pg_advisory_xact_lock(1, 1), pg_advisory_xact_lock_shared(2, 2);
ROLLBACK;
SELECT locktype, classid, objid, objsubid, mode, granted
FROM pg_locks WHERE locktype = 'advisory'
ORDER BY classid, objid, objsubid;
-- releasing all session locks
SELECT pg_advisory_unlock_all();
SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
BEGIN;
-- grabbing txn locks multiple times
SELECT
pg_advisory_xact_lock(1), pg_advisory_xact_lock(1),
pg_advisory_xact_lock_shared(2), pg_advisory_xact_lock_shared(2),
pg_advisory_xact_lock(1, 1), pg_advisory_xact_lock(1, 1),
pg_advisory_xact_lock_shared(2, 2), pg_advisory_xact_lock_shared(2, 2);
SELECT locktype, classid, objid, objsubid, mode, granted
FROM pg_locks WHERE locktype = 'advisory'
ORDER BY classid, objid, objsubid;
COMMIT;
SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
-- grabbing session locks multiple times
SELECT
pg_advisory_lock(1), pg_advisory_lock(1),
pg_advisory_lock_shared(2), pg_advisory_lock_shared(2),
pg_advisory_lock(1, 1), pg_advisory_lock(1, 1),
pg_advisory_lock_shared(2, 2), pg_advisory_lock_shared(2, 2);
SELECT locktype, classid, objid, objsubid, mode, granted
FROM pg_locks WHERE locktype = 'advisory'
ORDER BY classid, objid, objsubid;
SELECT
pg_advisory_unlock(1), pg_advisory_unlock(1),
pg_advisory_unlock_shared(2), pg_advisory_unlock_shared(2),
pg_advisory_unlock(1, 1), pg_advisory_unlock(1, 1),
pg_advisory_unlock_shared(2, 2), pg_advisory_unlock_shared(2, 2);
SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
-- .. and releasing them all at once
SELECT
pg_advisory_lock(1), pg_advisory_lock(1),
pg_advisory_lock_shared(2), pg_advisory_lock_shared(2),
pg_advisory_lock(1, 1), pg_advisory_lock(1, 1),
pg_advisory_lock_shared(2, 2), pg_advisory_lock_shared(2, 2);
SELECT locktype, classid, objid, objsubid, mode, granted
FROM pg_locks WHERE locktype = 'advisory'
ORDER BY classid, objid, objsubid;
SELECT pg_advisory_unlock_all();
SELECT count(*) FROM pg_locks WHERE locktype = 'advisory';
|
