Re: pgsql-server/src backend/storage/buffer/bufmgr ...

Jan Wieck wrote:
> Tom Lane wrote:
>
> > Jan Wieck <JanWieck(at)Yahoo(dot)com> writes:
>
> >> The whole point of the bgwriter is to give responsetimes a better
> >> variance, I never claimed that it will improve performance.
> >
> > I want to use it to improve reliability, by getting rid of our
> > dependence on sync(). The bgwriter can afford to wait for writes
> > to occur, so it should be able to use fsync or even O_SYNC.
>
> Agreed, that would be our long term strategy. And chances are that the
> 63 lines of code I added today for a functionality that is turned off by
> default will not completely screw up that plan.

We don't give people options that are useless. Are you sure this option
is useful? "Hey, it makes the system so slow, checkpoints are now 90%
faster!" :-)

> But as I see it, there is not even half of a proposal for all that yet.
> And people have response time spike problems caused by the checkpointer
> today. At least that is what I heard from the folks who where at our BOF
> in New York. Those people will not mind if the option we give them in
> 7.5 is replaced with something better in 8.0 again. But they mind a lot
> if we give them nothing because what we can do now is not optimal.

We need more discussion/proof before we add something like this, even if
it is only for one release.

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