diff --git a/doc/src/sgml/ref/checkpoint.sgml b/doc/src/sgml/ref/checkpoint.sgml index 506934be5dc8677f8a9a4a986b08b3aeee8c8699..83df9e6537f58682f085c4570c5cd763f960aeb5 100644 --- a/doc/src/sgml/ref/checkpoint.sgml +++ b/doc/src/sgml/ref/checkpoint.sgml @@ -1,8 +1,8 @@ -<!-- $Header: /cvsroot/pgsql/doc/src/sgml/ref/checkpoint.sgml,v 1.1 2001/01/13 03:11:12 petere Exp $ --> +<!-- $Header: /cvsroot/pgsql/doc/src/sgml/ref/checkpoint.sgml,v 1.2 2001/01/24 21:56:23 petere Exp $ --> <refentry id="sql-checkpoint"> <docinfo> - <date>2001-01-13</date> + <date>2001-01-24</date> </docinfo> <refmeta> @@ -12,7 +12,7 @@ <refnamediv> <refname>CHECKPOINT</refname> - <refpurpose>Force transaction log to disk</refpurpose> + <refpurpose>Force transaction log checkpoint</refpurpose> </refnamediv> <refsynopsisdiv> @@ -25,7 +25,20 @@ CHECKPOINT <title>Description</title> <para> - This documentation needs to be written. + Write-Ahead Logging (WAL) puts a checkpoint in the transaction log + every 300 seconds by default. (This may be changed by the run-time + configuration option <parameter>CHECKPOINT_TIMEOUT</parameter>.) + The <command>CHECKPOINT</command> command forces a checkpoint at + the point at which the command is issued. The next automatic + checkpoint will still happen after the original cycle expires. + </para> + + <para> + A checkpoint is a point in the transaction log sequence at which + all data files have been updated to reflect the information in the + log. All data files will be flushed to disk. Refer to the + <citetitle>PostgreSQL Administrator's Guide</citetitle> for more + information about the WAL system. </para> </refsect1>