Re: Bgwriter behavior

Tom Lane wrote:
> Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> > So what are we doing for 8.0?
>
> Well, it looks like RC2 has already crashed and burned --- I can't
> imagine that Marc will let us release without an RC3 given what was
> committed today, never mind the btree bug that Mark Wong seems to have
> found. So maybe we should just bite the bullet and do something real
> about this.
>
> I'm willing to code up a proposed patch for the two-track idea I
> suggested, and if anyone else has a favorite maybe they could write
> something too. But do we have the resources to test such patches and
> make a decision in the next few days?
>
> At the moment my inclination is to sit on what we have. I've not seen
> any indication that 8.0 is really worse than earlier releases; the most
> you could argue against it is that it's not as much better as we hoped.
> That's not grounds to muck around at the RC3 stage.

I remember the other difference between 8.0 and pre-8.0. When a backend
has to write a block in 8.0, it does a write _plus_ fsync(), while in
pre-8.0 it did only a write. There was a proposal to pass backend write
information to the background writer so it would know to fsync at
checkpoint, but it was decided that backend writing would be rare. I
think we have to rethink that assumption.

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