Re: 'pg_global' cannot be used as default_tablespace.

On Wednesday, November 1, 2023, Bruce Momjian <bruce(at)momjian(dot)us> wrote:

> On Tue, Nov 10, 2020 at 08:28:08AM +0000, PG Doc comments form wrote:
> > The following documentation comment has been logged on the website:
> >
> > Page: https://www.postgresql.org/docs/13/bug-reporting.html
> > Description:
> >
> > Tablespace 'pg_global' is one of the two auto-generated tablespace by
> > initdb, and 'pg_global' should not be used as the default_tablespace,
> since
> > it is used for shared system catalogs. However, none of these
> information is
> > recorded in the doc
> > https://www.postgresql.org/docs/11/runtime-config-client.html and
> > https://www.postgresql.org/docs/11/manage-ag-tablespaces.html. In case
> of
> > some mishandling to use 'pg_global' as a default_tablespace value, it is
> > better to record it in the doc of
> > https://www.postgresql.org/docs/11/manage-ag-tablespaces.html.
>
> I know this is three years old, but I am now looking at this email can
> can't see the problem:
>
> SET default_tablespace = 'pg_global';
>
> CREATE TABLE test (x int);
> ERROR: only shared relations can be placed in pg_global tablespace
>
> Did you want an error from the SET command?
>

That would probably be a decent addition but the request was for us to add
“it is not permissible to specify the pg_global tablespace for either
default_tablespace or temp_tablespace”. In the tablespace section per the
request but maybe also within the settings definition section.

David J.