Re: Caching (was Re: choosing the right platform)

How can we solve the problem of cache trashing when scanning large
tables?

Tom Lane wrote:
>
> Jean-Luc Lachance <jllachan(at)nsd(dot)ca> writes:
> > Shouldn't there be a way to lock some tables in PG cache?
>
> In my opinion, no. I do not think a manual locking feature could
> possibly be used effectively. It could very easily be abused to
> decrease net performance, though :-(
>
> It does seem that a smarter buffer management algorithm would be a good
> idea, but past experiments have failed to show any measurable benefit.
> Perhaps those experiments were testing the wrong conditions. I'd still
> be happy to see LRU(k) or some such method put in, if someone can prove
> that it actually does anything useful for us. (As best I recall, I only
> tested LRU-2 with pgbench. Perhaps Josh's benchmarking project will
> offer a wider variety of interesting scenarios.)
>
> regards, tom lane
>
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