Re: 'pg_global' cannot be used as default_tablespace.

On Wed, Nov  1, 2023 at 07:12:48PM -0400, Tom Lane wrote:
> Bruce Momjian  writes:
> > On Wed, Nov  1, 2023 at 06:32:37PM -0400, Tom Lane wrote:
> >> But it *is* permissible, unless we add code to reject it during
> >> SET as Bruce mentioned.  Which seems fairly pointless to me.  It's not
> >> like there is anything unclear about the CREATE TABLE error message.
> 
> > Yeah, from the report I thought something bad happened if you tried to
> > use it and that is why we had to document it.  By documenting it we are
> > just giving the user advice before they get the error.  I wrote up this
> > minimal patch which might have the right level of detail to avoid
> > errors, if people think this is useful.
> 
> I think this will lead to just as much confusion, because people
> will read it and expect that SET will fail.
> 
> If we need to document any more than we have now, we should point
> out in the CREATE TABLE man page that you can't create a table in
> the pg_global tablespace.  That will cover both this case and the
> case of trying to select pg_global explicitly in the CREATE.
> 
> Another idea could be to adjust this bit in manage-ag.sgml:
> 
>    Two tablespaces are automatically created when the database cluster
>    is initialized.  The
> -  pg_global tablespace is used for shared system catalogs. The
> +  pg_global tablespace is used for shared system catalogs,
> +  and cannot be used for user-defined tables. The
>    pg_default tablespace is the default tablespace of the

I like the manage-ag.sgml change myself.

-- 
  Bruce Momjian          https://momjian.us
  EDB                                      https://enterprisedb.com

  Only you can decide what is important to you.