On Fri, Jan 29, 2010 at 4:13 AM, Simon Riggs <si...@2ndquadrant.com> wrote: > Hmm, I'm sorry but that's bogus. Retaining so much WAL that we are > strongly in danger of blowing disk space is not what I would call a > safety feature. Since there is no way to control or restrain the number > of files for certain, that approach seems fatally flawed. Reducing > checkpoint_timeout is the opposite of what you would want to do for > performance.
Why do you worry about that only in the standby? The primary (i.e., postgres in the normal mode) has been in the same situation until now. But usually the cycle of restartpoint is longer than that of checkpoint. Because restartpoint occurs when the checkpoint record has been replayed AND checkpoint_timeout has been reached. So the WAL files might more easily accumulate in the standby. To improve the situation, I think that we need to use checkpoint_segment/timeout as a trigger of restartpoint, regardless of the checkpoint record. Though I'm not sure that is possible and should be included in v9.0. Regards, -- Fujii Masao NIPPON TELEGRAPH AND TELEPHONE CORPORATION NTT Open Source Software Center -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
