On Wed, Nov 2, 2011 at 4:15 PM, Robert Haas <robertmhaas@gmail.com> wrote:
> On Wed, Nov 2, 2011 at 11:39 AM, Simon Riggs <simon@2ndquadrant.com> wrote:
>> Reduce checkpoints and WAL traffic on low activity database server
>> Previously, we skipped a checkpoint if no WAL had been written since
>> last checkpoint, though this does not appear in user documentation.
>> As of now, we skip a checkpoint until we have written at least one
>> enough WAL to switch the next WAL file. This greatly reduces the
>> level of activity and number of WAL messages generated by a very
>> low activity server. This is safe because the purpose of a checkpoint
>> is to act as a starting place for a recovery, in case of crash.
>> This patch maintains minimal WAL volume for replay in case of crash,
>> thus maintaining very low crash recovery time.
>
> I think you need to update the docs, for checkpoint_timeout if nothing else.
Checkpoints have always been skipped, if no activity. So the docs
don't need changing.
--
Simon Riggs http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services
