Re: Caching (was Re: choosing the right platform) - Mailing list pgsql-performance

From Jean-Luc Lachance
Subject Re: Caching (was Re: choosing the right platform)
Date
Msg-id 3E95BF2B.B93FD0EF@nsd.ca
Whole thread Raw
In response to Re: choosing the right platform  ("Matthew Nuzum" <cobalt@bearfruit.org>)
List pgsql-performance
How can we solve the problem of cache trashing when scanning large
tables?

Tom Lane wrote:
>
> Jean-Luc Lachance <jllachan@nsd.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
>
> ---------------------------(end of broadcast)---------------------------
> TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org


pgsql-performance by date:

Previous
From: "Patrick Hatcher"
Date:
Subject: Re: Slow Visual Basic application
Next
From: "Ron Mayer"
Date:
Subject: Re: Caching (was Re: choosing the right platform)