Message-ID: <47B56651.9050600@archonet.com>
Date: Fri, 15 Feb 2008 10:15:45 +0000
From: Richard Huxton <dev@archonet.com>
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To: Bart Degryse <Bart.Degryse@indicator.be>
CC: PostgreSQL SQL List <pgsql-sql@postgresql.org>
Subject: Re: Function description
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Dont' forget to cc: the list Bart :-)

Bart Degryse wrote:
> Thanks for that explanation Richard.
> But how can I know what they repeat without having documentation.
> I mean, how about functions like eg regexeqjoinsel, regexeqsel, reltimeeq, reltimege.
> I can imagine they mimic some other functionality, but how can I know whichone?

Well, like I said many implement operators, so they can be obviously be 
found in pg_operator:

SELECT * FROM pg_operator WHERE oprcode = 'reltimeeq'::regproc;

The oprleft/right/result columns hold oid numbers for types in pg_type.

Casts are listed in pg_cast etc.

The fine manuals detail the system catalogues in a chapter "System 
Catalogs".
http://www.postgresql.org/docs/8.3/static/catalogs.html

To see how e.g. \dC etc work start psql with -E

If it's not documented though, you need to ask two questions:
1. Why am I using it?
2. Will it be there in the next version?

-- 
   Richard Huxton
   Archonet Ltd