Re: clear function cache (WAS: SQL function inlining)

From: Enrico Weigelt <weigelt(at)metux(dot)de>
To: pgsql-performance(at)postgresql(dot)org
Subject: Re: clear function cache (WAS: SQL function inlining)
Date: 2005-03-24 14:12:33
Message-ID: 20050324141233.GA933@nibiru.borg.metux.de
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* Alvaro Herrera <alvherre(at)dcc(dot)uchile(dot)cl> wrote:
> On Thu, Mar 24, 2005 at 02:32:48PM +0100, Enrico Weigelt wrote:
>
> > BTW: is it possible to explicitly clear the cache for immutable
> > functions ?
>
> What cache? There is no caching of function results.

Not ? So what's immutable for ?

<snip>
> > I'd like to use immutable functions for really often lookups like
> > fetching a username by uid and vice versa. The queried tables
> > change very rarely, but when they change is quite unpredictable.
>
> Maybe you should use a stable function if you fear we'll having function
> result caching without you noticing.

hmm, this makes more real evaluations necessary than w/ immuatable.
AFAIK stable functions have to be evaluated once per query, and the
results are not cached between several queries.

cu
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