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
|
'\" t
.\" Title: SAVEPOINT
.\" Author: The PostgreSQL Global Development Group
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\" Date: 2024
.\" Manual: PostgreSQL 15.7 Documentation
.\" Source: PostgreSQL 15.7
.\" Language: English
.\"
.TH "SAVEPOINT" "7" "2024" "PostgreSQL 15.7" "PostgreSQL 15.7 Documentation"
.\" -----------------------------------------------------------------
.\" * Define some portability stuff
.\" -----------------------------------------------------------------
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.\" http://bugs.debian.org/507673
.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.ie \n(.g .ds Aq \(aq
.el .ds Aq '
.\" -----------------------------------------------------------------
.\" * set default formatting
.\" -----------------------------------------------------------------
.\" disable hyphenation
.nh
.\" disable justification (adjust text to left margin only)
.ad l
.\" -----------------------------------------------------------------
.\" * MAIN CONTENT STARTS HERE *
.\" -----------------------------------------------------------------
.SH "NAME"
SAVEPOINT \- define a new savepoint within the current transaction
.SH "SYNOPSIS"
.sp
.nf
SAVEPOINT \fIsavepoint_name\fR
.fi
.SH "DESCRIPTION"
.PP
\fBSAVEPOINT\fR
establishes a new savepoint within the current transaction\&.
.PP
A savepoint is a special mark inside a transaction that allows all commands that are executed after it was established to be rolled back, restoring the transaction state to what it was at the time of the savepoint\&.
.SH "PARAMETERS"
.PP
\fIsavepoint_name\fR
.RS 4
The name to give to the new savepoint\&. If savepoints with the same name already exist, they will be inaccessible until newer identically\-named savepoints are released\&.
.RE
.SH "NOTES"
.PP
Use
\fBROLLBACK TO\fR
to rollback to a savepoint\&. Use
\fBRELEASE SAVEPOINT\fR
to destroy a savepoint, keeping the effects of commands executed after it was established\&.
.PP
Savepoints can only be established when inside a transaction block\&. There can be multiple savepoints defined within a transaction\&.
.SH "EXAMPLES"
.PP
To establish a savepoint and later undo the effects of all commands executed after it was established:
.sp
.if n \{\
.RS 4
.\}
.nf
BEGIN;
INSERT INTO table1 VALUES (1);
SAVEPOINT my_savepoint;
INSERT INTO table1 VALUES (2);
ROLLBACK TO SAVEPOINT my_savepoint;
INSERT INTO table1 VALUES (3);
COMMIT;
.fi
.if n \{\
.RE
.\}
.sp
The above transaction will insert the values 1 and 3, but not 2\&.
.PP
To establish and later destroy a savepoint:
.sp
.if n \{\
.RS 4
.\}
.nf
BEGIN;
INSERT INTO table1 VALUES (3);
SAVEPOINT my_savepoint;
INSERT INTO table1 VALUES (4);
RELEASE SAVEPOINT my_savepoint;
COMMIT;
.fi
.if n \{\
.RE
.\}
.sp
The above transaction will insert both 3 and 4\&.
.PP
To use a single savepoint name:
.sp
.if n \{\
.RS 4
.\}
.nf
BEGIN;
INSERT INTO table1 VALUES (1);
SAVEPOINT my_savepoint;
INSERT INTO table1 VALUES (2);
SAVEPOINT my_savepoint;
INSERT INTO table1 VALUES (3);
\-\- rollback to the second savepoint
ROLLBACK TO SAVEPOINT my_savepoint;
SELECT * FROM table1; \-\- shows rows 1 and 2
\-\- release the second savepoint
RELEASE SAVEPOINT my_savepoint;
\-\- rollback to the first savepoint
ROLLBACK TO SAVEPOINT my_savepoint;
SELECT * FROM table1; \-\- shows only row 1
COMMIT;
.fi
.if n \{\
.RE
.\}
.sp
The above transaction shows row 3 being rolled back first, then row 2\&.
.SH "COMPATIBILITY"
.PP
SQL requires a savepoint to be destroyed automatically when another savepoint with the same name is established\&. In
PostgreSQL, the old savepoint is kept, though only the more recent one will be used when rolling back or releasing\&. (Releasing the newer savepoint with
\fBRELEASE SAVEPOINT\fR
will cause the older one to again become accessible to
\fBROLLBACK TO SAVEPOINT\fR
and
\fBRELEASE SAVEPOINT\fR\&.) Otherwise,
\fBSAVEPOINT\fR
is fully SQL conforming\&.
.SH "SEE ALSO"
\fBBEGIN\fR(7), \fBCOMMIT\fR(7), RELEASE SAVEPOINT (\fBRELEASE_SAVEPOINT\fR(7)), \fBROLLBACK\fR(7), ROLLBACK TO SAVEPOINT (\fBROLLBACK_TO_SAVEPOINT\fR(7))
|
