To: Hiroshi Inoue <Inoue@tpf.co.jp>
cc: Bill Studenmund <wrstuden@netbsd.org>, Peter Eisentraut <peter_e@gmx.net>,
	PostgreSQL Development <pgsql-hackers@postgresql.org>
Subject: Re: RFD: schemas and different kinds of Postgres objects 
In-reply-to: <3C58A472.2E90C21C@tpf.co.jp> 
References: 
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	<3C573C5E.F01B48C2@tpf.co.jp> <27527.1012432386@sss.pgh.pa.us>
	<3C58A472.2E90C21C@tpf.co.jp>
Comments: In-reply-to Hiroshi Inoue <Inoue@tpf.co.jp>
	message dated "Thu, 31 Jan 2002 10:57:06 +0900"
Date: Wed, 30 Jan 2002 21:32:10 -0500
Message-ID: <29268.1012444330@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>

Hiroshi Inoue <Inoue@tpf.co.jp> writes:
> I have no objection to the point it makes sense to use
> such *path*s internally but I think it also has a siginificance
> for SQL-path to not look up _tables_like objects. 
> I think they are different from the first and we should(need)
> not manage the system with one *path*.

I'm unconvinced.  We must search for datatypes and tables on the same
path because tables have associated datatypes; it will definitely not
do to look for a table's datatype and get the wrong type.  And I think
that functions and operators should be looked for on the same path
as datatypes, because a type should be pretty closely associated with
the functions/operators for it.  So it seems to me that the apparent
flexibility of having more than one path is just a way to shoot yourself
in the foot.  Why are you concerned that we keep them separate?

> BTW I see few references to *catalog*. Would the concept
> of catalog be introduced together. If so what would be
> contained in the current database.

My thought is that we will consider catalog == database.  As far as
I can tell, that is a legitimate implementation-defined way of
interpreting the spec.  (It's not clear to me what the value is of
having more than one level of schema hierarchy; or at least, if you want
hierarchical namespaces, there's no argument for stopping at depth two.
But I digress.)  To satisfy the spec we must allow a (purely decorative)
specification of the current database name as the catalog level of a
qualified name, but that's as far as I want to go.  In this round,
anyway.  Cross-database access is not something to tackle for 7.3.

			regards, tom lane