From: Tom Lane <tgl@sss.pgh.pa.us>
To: marc@guidance.nl
cc: pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #16758: create temporary table with the same name loses
 defaults, indexes
In-reply-to: <16758-840e84a6cfab276d@postgresql.org>
References: <16758-840e84a6cfab276d@postgresql.org>
Comments: In-reply-to PG Bug reporting form <noreply@postgresql.org>
	message dated "Tue, 01 Dec 2020 14:09:49 +0000"
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-ID: <1396478.1606838336.1@sss.pgh.pa.us>
Content-Transfer-Encoding: quoted-printable
Date: Tue, 01 Dec 2020 10:58:56 -0500
Message-ID: <1396479.1606838336@sss.pgh.pa.us>
Precedence: bulk

PG Bug reporting form <noreply@postgresql.org> writes:
> In 12.5 (and later), in a clean, empty database (in this case the defaul=
t
> 12.5 docker image), when I execute the following lines:

>     create table xx (name text NOT NULL default '', PRIMARY KEY(name));
>     create temporary table xx
>         (like xx including DEFAULTS including CONSTRAINTS including INDE=
XES);

Hm, interesting.  Without having dug into the code, I bet what is
happening is that after creating pg_temp.xx, the LIKE code is looking
to see "what indexes exist on table xx?", to which the answer is "none"
because it finds pg_temp.xx.  We need to nail down the schema in which
xx is sought for that step.  As a workaround, you could nail down the
schema manually:

create temporary table xx (like public.xx including DEFAULTS including
CONSTRAINTS including INDEXES);

The ordering of these operations got rearranged recently to fix some
other bugs, so it doesn't surprise me if it used to work differently.

			regards, tom lane