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3 <refentry id="sql-checkpoint">
5 <refentrytitle id="sql-checkpoint-title">CHECKPOINT</refentrytitle>
6 <refmiscinfo>SQL - Language Statements</refmiscinfo>
10 <refname>CHECKPOINT</refname>
11 <refpurpose>force a transaction log checkpoint</refpurpose>
14 <indexterm zone="sql-checkpoint">
15 <primary>CHECKPOINT</primary>
25 <title>Description</title>
28 Write-Ahead Logging (WAL) puts a checkpoint in the transaction log
29 every so often. (To adjust the automatic checkpoint interval, see
30 the run-time configuration options <xref linkend="guc-checkpoint-segments">
31 and <xref linkend="guc-checkpoint-timeout">.) The
32 <command>CHECKPOINT</command> command forces an immediate
33 checkpoint when the command is issued, without waiting for a
38 A checkpoint is a point in the transaction log sequence at which
39 all data files have been updated to reflect the information in the
40 log. All data files will be flushed to disk. Refer to
41 <xref linkend="wal"> for more information about the WAL system.
45 Only superusers may call <command>CHECKPOINT</command>. The command is
46 not intended for use during normal operation.
51 <title>Compatibility</title>
54 The <command>CHECKPOINT</command> command is a
55 <productname>PostgreSQL</productname> language extension.
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