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diff --git a/doc/src/sgml/man7/RELEASE_SAVEPOINT.7 b/doc/src/sgml/man7/RELEASE_SAVEPOINT.7 new file mode 100644 index 0000000..1761ead --- /dev/null +++ b/doc/src/sgml/man7/RELEASE_SAVEPOINT.7 @@ -0,0 +1,127 @@ +'\" t +.\" Title: RELEASE SAVEPOINT +.\" Author: The PostgreSQL Global Development Group +.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/> +.\" Date: 2024 +.\" Manual: PostgreSQL 16.2 Documentation +.\" Source: PostgreSQL 16.2 +.\" Language: English +.\" +.TH "RELEASE SAVEPOINT" "7" "2024" "PostgreSQL 16.2" "PostgreSQL 16.2 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" +RELEASE_SAVEPOINT \- release a previously defined savepoint +.SH "SYNOPSIS" +.sp +.nf +RELEASE [ SAVEPOINT ] \fIsavepoint_name\fR +.fi +.SH "DESCRIPTION" +.PP +\fBRELEASE SAVEPOINT\fR +releases the named savepoint and all active savepoints that were created after the named savepoint, and frees their resources\&. All changes made since the creation of the savepoint that didn\*(Aqt already get rolled back are merged into the transaction or savepoint that was active when the named savepoint was created\&. Changes made after +\fBRELEASE SAVEPOINT\fR +will also be part of this active transaction or savepoint\&. +.SH "PARAMETERS" +.PP +\fIsavepoint_name\fR +.RS 4 +The name of the savepoint to release\&. +.RE +.SH "NOTES" +.PP +Specifying a savepoint name that was not previously defined is an error\&. +.PP +It is not possible to release a savepoint when the transaction is in an aborted state; to do that, use +ROLLBACK TO SAVEPOINT (\fBROLLBACK_TO_SAVEPOINT\fR(7))\&. +.PP +If multiple savepoints have the same name, only the most recently defined unreleased one is released\&. Repeated commands will release progressively older savepoints\&. +.SH "EXAMPLES" +.PP +To establish and later release 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 +A more complex example with multiple nested subtransactions: +.sp +.if n \{\ +.RS 4 +.\} +.nf +BEGIN; + INSERT INTO table1 VALUES (1); + SAVEPOINT sp1; + INSERT INTO table1 VALUES (2); + SAVEPOINT sp2; + INSERT INTO table1 VALUES (3); + RELEASE SAVEPOINT sp2; + INSERT INTO table1 VALUES (4))); \-\- generates an error +.fi +.if n \{\ +.RE +.\} +.sp +In this example, the application requests the release of the savepoint +sp2, which inserted 3\&. This changes the insert\*(Aqs transaction context to +sp1\&. When the statement attempting to insert value 4 generates an error, the insertion of 2 and 4 are lost because they are in the same, now\-rolled back savepoint, and value 3 is in the same transaction context\&. The application can now only choose one of these two commands, since all other commands will be ignored: +.sp +.if n \{\ +.RS 4 +.\} +.nf + ROLLBACK; + ROLLBACK TO SAVEPOINT sp1; +.fi +.if n \{\ +.RE +.\} +.sp +Choosing +\fBROLLBACK\fR +will abort everything, including value 1, whereas +\fBROLLBACK TO SAVEPOINT sp1\fR +will retain value 1 and allow the transaction to continue\&. +.SH "COMPATIBILITY" +.PP +This command conforms to the +SQL +standard\&. The standard specifies that the key word +SAVEPOINT +is mandatory, but +PostgreSQL +allows it to be omitted\&. +.SH "SEE ALSO" +\fBBEGIN\fR(7), \fBCOMMIT\fR(7), \fBROLLBACK\fR(7), ROLLBACK TO SAVEPOINT (\fBROLLBACK_TO_SAVEPOINT\fR(7)), \fBSAVEPOINT\fR(7) |