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.

Oh, is it that bad?

> 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.

That was my question. It seems bgwriter is fine for low to medium
traffic but doesn't handle high traffic, and increasing the scan rate
makes things worse.

I am fine with doing nothing, but if we are going to do something, I
would like to do it now rather than later.

The only way I could see it being worse than pre-8.0 is that the
bgwriter is doing fsync of all open files rather than using sync. Other
than that, I think it should behave the same, or slightly better,
right?

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