On Fri, Jun 8, 2012 at 9:58 AM, Simon Riggs <si...@2ndquadrant.com> wrote: > On 8 June 2012 14:47, Robert Haas <robertmh...@gmail.com> wrote: > >>> ISTM that we should avoid triggering a checkpoint on the master if >>> checkpoint_segments is less than wal_keep_segments. Such checkpoints >>> serve no purpose because we don't actually limit and recycle the WAL >>> files and all it does is slow people down. >> >> On the other hand, I emphatically disagree with this, for the same >> reasons as on the other thread. Getting data down to disk provides a >> greater measure of safety than having it in memory. Making >> checkpoint_segments not force a checkpoint is no better than making >> checkpoint_timeout not force a checkpoint. > > Not sure which bit you are disagreeing with. I have no suggested > change to checkpoint_timeout.
You already made it not a hard timeout. We have another nearby thread discussing why I don't like that. > What I'm saying is that forcing a checkpoint to save space, when we > aren't going to save space, makes no sense. We are also forcing a checkpoint to limit recovery time and data loss potential, not just to save space. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
