On Sat, Mar 1, 2008 at 2:13 AM, Heikki Linnakangas <[EMAIL PROTECTED]> wrote: > > > I used to think it's a big problem, but I believe the full-page-write > optimization in 8.3 made it much less so. Especially with the smoothed > checkpoints: as checkpoints have less impact on response times, you can > shorten checkpoint interval, which helps to keep the recovery time > reasonable. >
I agree that smoothed checkpoints have considerably removed the response time spikes we used to see in TPCC tests. What I still don't like about the current checkpoint mechanism that it writes all the dirty buffers to disk. With very large shared buffers, this could still be a problem. Someday we may want to implement LAZY checkpoints which does not require writing dirty pages and hence can be taken much more frequently. But lazy checkpoints can increase the amount of redo work to be done at the recovery time. If we can significantly improve the recovery logic, we can then think of reducing the work done at the checkpoint time (either through lazy checkpoints or less frequent hard checkpoints) which would benefit the normal database operation. Thanks, Pavan -- Pavan Deolasee EnterpriseDB http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your Subscription: http://mail.postgresql.org/mj/mj_wwwusr?domain=postgresql.org&extra=pgsql-hackers