Re: Multiple buffer cache? - Mailing list pgsql-general

From Tom Lane
Subject Re: Multiple buffer cache?
Date
Msg-id 18596.1265524536@sss.pgh.pa.us
Whole thread Raw
In response to Re: Multiple buffer cache?  (Greg Smith <greg@2ndquadrant.com>)
Responses Re: Multiple buffer cache?  (Greg Stark <stark@mit.edu>)
List pgsql-general
Greg Smith <greg@2ndquadrant.com> writes:
> ...  Part of the reason this feature
> hasn't been been perceived as more valuable is because just letting the
> two cache levels involved here sort out what's really valuable or not
> can often outperform what an application developer thinks the optimal
> configuration will be.

Or to put it even more clearly: the only way that pinning particular
tables into RAM could beat letting the caching algorithm take care of
it is if the caching algorithm is seriously suboptimal.  Therefore,
it would make more sense to put development effort into improving
the cache algorithm than to put it into giving the DBA a rather blunt
instrument for overriding the cache algorithm.  We've already made
several rounds of improvements of that kind, and are quite happy to
consider more.

            regards, tom lane

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