Hi, On Fri, Dec 5, 2008 at 7:09 PM, Simon Riggs <[EMAIL PROTECTED]> wrote: > > On Fri, 2008-12-05 at 12:09 +0900, Fujii Masao wrote: > >> On Thu, Dec 4, 2008 at 6:29 PM, Simon Riggs <[EMAIL PROTECTED]> wrote: >> > The only sensible settings are >> > synchronous_commit = on, synchronous_replication = on >> > synchronous_commit = on, synchronous_replication = off >> > synchronous_commit = off, synchronous_replication = off >> > >> > This doesn't make any sense: (does it??) >> > synchronous_commit = off, synchronous_replication = on >> >> If the standby replies before writing the WAL, that strategy can improve >> the performance with moderate reliability, and sounds sensible. > > Do you think it likely that your replication time is consistently and > noticeably less than your time-to-disk?
It depends on a system environment. - How many miles two servers? same rack? separate continent? - Does system have high-end storage? cheap one? ... etc > > On a related thought: presumably we force a sync rep if forceSyncCommit > is set? Yes! Please see RecordTransactionCommit() in xact.c (in my patch). 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
