From: Tom Lane <tgl@sss.pgh.pa.us>
To: Isaac Morland <isaac.morland@gmail.com>
cc: Pavel Stehule <pavel.stehule@gmail.com>,
        Ron Johnson <ronljohnsonjr@gmail.com>,
        pgsql-general <pgsql-general@postgresql.org>
Subject: Re: Request for new column in pg_namespace
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Comments: In-reply-to Isaac Morland <isaac.morland@gmail.com>
	message dated "Sun, 15 Dec 2024 12:40:12 -0500"
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Date: Sun, 15 Dec 2024 14:20:23 -0500
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Isaac Morland <isaac.morland@gmail.com> writes:
> On Sun, 15 Dec 2024 at 12:29, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> What I'd suggest as an improvement that could be implemented
>> immediately is to wrap the checks in a user-defined function
>> like "is_system_schema(nspname name)".

> Would it make sense to make the parameter be of type regnamespace?

Meh ... you could, but what the function really needs is the name.
Getting from regnamespace (which is an OID) to the name would incur
an extra syscache lookup.  Admittedly, if it removes the need for
the calling query to join to pg_namespace at all, you'd probably
come out about even --- the net effect would be about like a
hashjoin to pg_namespace, I think, since the syscache would act
like the inner hashtable of a hashjoin.

			regards, tom lane