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