From: dg@illustra.com (David Gould)
Message-Id: <9803241917.AA18817@hawk.illustra.com>
Subject: Re: [HACKERS] char types gone.
To: darrenk@insightdist.com (Darren King)
Date: Tue, 24 Mar 1998 11:17:40 -0800 (PST)
Cc: pgsql-hackers@postgreSQL.org
In-Reply-To: <9803241510.AA33040@ceodev> from "Darren King" at Mar 24,
	98 10:10:05 am
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> > > I don't know how big of a performance boost it provides in the cache, but
> > > removing the functions associated with the char types shrank the pg_proc
> > > table from 906 to 842 entries or a bit over 7%.

No performance impact.

> > > Want to shrink it further?  Of those remaining 842, _230_ are for the geometric
> > > types!  Throw in 25 more for the cash/money functions.  Bloat city if you
> > > never use these things.  Thirty percent could be moved out to contrib and
> > > not missed by most postgres users.
> > 
> > Yes, but if they are never referenced, the cache is empty for those
> > types.  Unless there is some performance change with their removal, why
> > remove them?  Disk space of binary?
> 
> How does the cache really work then? Does one pg disk block map to one buffer?
> 
> When you say "the cache is empty for those types.", what do you mean?

The function cache has one entry for each function in use. If a function has
never been called, then no cache entry is ever created for it. The cache
is organized per function, it is not part of the buffer / page cache so
each entry only takes a few bytes.

-dg

David Gould            dg@illustra.com           510.628.3783 or 510.305.9468 
Informix Software  (No, really)         300 Lakeside Drive  Oakland, CA 94612
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