Re: RE: [COMMITTERS] pgsql/src/backend/access/transam ( xact.c xlog.c)

Bruce Momjian <pgman@candle.pha.pa.us> writes:
>> I have to agree with Alfred here: this does not sound like a feature,
>> it sounds like a horrid hack.  You're giving up *all* consistency
>> guarantees for a performance gain that is really going to be pretty
>> minimal in the WAL context.

> It does not give up consistency.  The db is still consistent, it is just
> consistent from a few seconds ago, rather than commit time.

No, it isn't consistent.  Without the fsync you don't know what order
the kernel will choose to plop down WAL log blocks in; you could end up
with a corrupt log.  (Actually, perhaps that could be worked around if
the log blocks are suitably marked so that you can tell where the last
sequentially valid one is.  I haven't looked at the log structure in
any detail...)
        regards, tom lane