Re: Allowing WAL fsync to be done via O_SYNC

Bruce Momjian <pgman@candle.pha.pa.us> writes:
> I was wondering if the multiple writes performed to the XLOG could be
> grouped into one write().

That would require fairly major restructuring of xlog.c, which I don't
want to undertake at this point in the cycle (we're trying to push out
a release candidate, remember?).  I'm not convinced it would be a huge
win anyway.  It would be a win if your average transaction writes
multiple blocks' worth of XLOG ... but if your average transaction
writes less than a block then it won't help.

I think it probably is a good idea to restructure xlog.c so that it can
write more than one page at a time --- but it's not such a great idea
that I want to hold up the release any more for it.
        regards, tom lane