Re: add \dpS to psql

On Wed, 28 Dec 2022 at 21:26, Nathan Bossart <nathandbossart@gmail.com> wrote:
>
> On Wed, Dec 28, 2022 at 02:46:23PM +0300, Maxim Orlov wrote:
> > The patch applies with no problem, implements what it declared, CF bot is
> > happy.
> > Without patch \dpS shows 0 rows, after applying system objects are shown.
> > Consider this patch useful, hope it will be committed soon.
>
> Thanks for reviewing.
>

Looking this over this, I have a couple of comments:

Firstly, I think it should allow \zS in the same fashion as \dpS,
since \z is an alias for \dp, so the 2 should be kept in sync.

Secondly, I don't think the following is the right SQL clause to use
in the absence of "S":

    if (!showSystem && !pattern)
        appendPQExpBufferStr(&buf, "AND n.nspname !~ '^pg_'\n");

I know that's the condition it used before, but the problem with using
that now is that it will cause temporary relations to be excluded
unless the "S" modifier is used, which goes against the expectation
that "S" just causes system relations to be included. Also, it fails
to exclude information_schema relations, if that happens to be on the
user's search_path.

So I think we should use the same SQL clauses as every other psql
command that supports "S", namely:

    if (!showSystem && !pattern)
        appendPQExpBufferStr(&buf, "      AND n.nspname <> 'pg_catalog'\n"
                             "      AND n.nspname <> 'information_schema'\n");

Updated patch attached.

Regards,
Dean