Robert Haas <robertmh...@gmail.com> writes: > ... How often such a workload actually has to replace a *dirty* clog > buffer obviously depends on how often you checkpoint, but if you're > getting ~28k TPS you can completely fill 32 clog buffers (1 million > transactions) in less than 40 seconds, and you're probably not > checkpointing nearly that often.
But by the same token, at that kind of transaction rate, no clog page is actively getting dirtied for more than a couple of seconds. So while it might get swapped in and out of the SLRU arena pretty often after that, this scenario seems unconvincing as a source of repeated fsyncs. Like Andres, I'd want to see a more realistic problem case before expending a lot of work here. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers