From: Tom Lane <tgl@sss.pgh.pa.us>
To: Pavel Stehule <pavel.stehule@gmail.com>
cc: 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 Pavel Stehule <pavel.stehule@gmail.com>
	message dated "Sun, 15 Dec 2024 18:15:57 +0100"
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Date: Sun, 15 Dec 2024 12:29:26 -0500
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Pavel Stehule <pavel.stehule@gmail.com> writes:
> ne 15. 12. 2024 v 17:59 odesílatel Ron Johnson <ronljohnsonjr@gmail.com>
> napsal:
>> A new boolean column named "indissystem" that's true only for system
>> relations would make *many* maintenance queries cleaner, since they'd
>> look like:
>> select ...

> oid of all system objects is less then 0x4000

That wouldn't help for excluding temp schemas, and it's not totally
trustworthy for information_schema either.

But I think the real problem with Ron's proposal is that it presumes
there is a one-size-fits-all notion of "system schema".  As a
counterexample, for some maintenance activities (such as vacuuming)
you might wish to process pg_catalog.

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)".

			regards, tom lane