To: Dimitri Fontaine <dimitri@2ndQuadrant.fr>
cc: pgsql-hackers@postgresql.org, pgsql-docs@postgresql.org
Subject: Re: [HACKERS] "Extension" versus "module" 
In-reply-to: <m2wrl2k2tv.fsf@2ndQuadrant.fr> 
References: <25160.1297664305@sss.pgh.pa.us> <87r5ba4z1x.fsf@2ndQuadrant.fr>
	<20217.1297697118@sss.pgh.pa.us> <m2wrl2k2tv.fsf@2ndQuadrant.fr>
Comments: In-reply-to Dimitri Fontaine <dimitri@2ndQuadrant.fr>
	message dated "Mon, 14 Feb 2011 17:17:48 +0100"
Date: Mon, 14 Feb 2011 11:32:52 -0500
Message-ID: <25496.1297701172@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>

Dimitri Fontaine <dimitri@2ndQuadrant.fr> writes:
> Another concern has to do with PLs.  We said that with the dependency
> mechanism it would be good to have PLs be EXTENSIONs.  But those are
> core provided extensions, one of them installed by default.

> If we make PLs extensions, we might also want to have CREATE LANGUAGE
> either ERROR out or silently do the CREATE EXTENSION instead, meaning
> that CREATE LANGUAGE behavior would depend on creating_extension.
> Sounds like a crock but ensures compatibility.

Yeah.  I was sort of wondering whether we could get rid of pg_pltemplate
altogether, and instead rely on the extension mechanism to package up
the correct parameters for installing a language.  However, one thing
that'd have to be solved before going very far in this direction is the
question of allowing CREATE EXTENSION to non-superusers.  We'd at least
need to be able to duplicate the current functionality of allowing
CREATE LANGUAGE to database owners (with an override available to the
DBA).

This seems like a matter for a separate thread though, and not on
pgsql-docs.

			regards, tom lane