Re: RC2 and open issues

Tom Lane wrote:
> Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> > I am confused. If we change the percentage to be X% of the entire
> > buffer cache, and we set it to 1%, and we exit when either the dirty
> > pages or % are reached, don't we end up just scanning the first 1% of
> > the cache over and over again?
>
> Exactly. But 1% would be uselessly small with this definition. Offhand
> I'd think something like 50% might be a starting point; maybe even more.
> What that says is that a page isn't a candidate to be written out by the
> bgwriter until it's fallen halfway down the LRU list.

So we are not scanning by buffer address but using the LRU list? Are we
sure they are mostly dirty?

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