From d561fc5396e537452065c3531cb43edf11a8dbf0 Mon Sep 17 00:00:00 2001 From: Robert Haas Date: Thu, 30 Aug 2012 15:06:55 -0400 Subject: [PATCH] Fix checkpoint_timeout documentation to reflect current behavior. Jeff Janes --- doc/src/sgml/wal.sgml | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/doc/src/sgml/wal.sgml b/doc/src/sgml/wal.sgml index e34faffce2a..b21afce4b79 100644 --- a/doc/src/sgml/wal.sgml +++ b/doc/src/sgml/wal.sgml @@ -424,12 +424,10 @@ linkend="guc-checkpoint-segments"> log segments, or every seconds, whichever comes first. The default settings are 3 segments and 300 seconds (5 minutes), respectively. - In cases where little or no WAL has been written, checkpoints will be - skipped even if checkpoint_timeout has passed. At least one new WAL segment - must have been created before an automatic checkpoint occurs. The time - between checkpoints and when new WAL segments are created are not related - in any other way. If file-based WAL shipping is being used and you want to - bound how often files are sent to standby server to reduce potential data + In cases where no WAL has been written since the previous checkpoint, new + checkpoints will be skipped even if checkpoint_timeout has passed. + If WAL archiving is being used and you want to put a lower limit on + how often files are archived in order to bound potential data loss, you should adjust archive_timeout parameter rather than the checkpoint parameters. It is also possible to force a checkpoint by using the SQL command CHECKPOINT.