Re: Fuzzy thinking in is_publishable_class

I wrote:
> is_publishable_class has a test "relid >= FirstNormalObjectId",
> which I think we should drop, for two reasons:

> 1. It makes the comment claiming that this function tests the same
> things as check_publication_add_relation a lie.

> 2. The comment about it claims that the purpose is to reject
> information_schema relations, but if that's so, it's ineffective.
> We consider it supported to drop and recreate information_schema,
> and have indeed recommended doing so for some minor-version
> upgrades. After that, the information_schema relations would no
> longer have OIDs recognizable to this test.

> So what is the motivation for this test? If there's an important
> reason for it, we need to find a less fragile way to express it.

After further digging around, I wonder whether this test wasn't
somehow related to the issue described in

https://postgr.es/m/2321.1557263978@sss.pgh.pa.us

That doesn't completely make sense, since the restriction on
relkind should render it moot whether IsCatalogClass thinks
that a toast table is a catalog table, but maybe there's a link?

regards, tom lane