Re: [GENERAL] pg_upgrade & tablespaces

On Sat, Jan 11, 2014 at 12:48:51PM -0800, Adrian Klaver wrote:
> >pg_upgrade looks in the pg_tablespace in pre-9.2, and uses a function in
> >9.2+.  The query is:
> >
> >     snprintf(query, sizeof(query),
> >              "SELECT    %s "
> >              "FROM  pg_catalog.pg_tablespace "
> >              "WHERE spcname != 'pg_default' AND "
> >              "      spcname != 'pg_global'",
> >     /* 9.2 removed the spclocation column */
> >              (GET_MAJOR_VERSION(old_cluster.major_version) <= 901) ?
> >--> "spclocation" : "pg_catalog.pg_tablespace_location(oid) AS spclocation");
>
>
> I see, though I have another question. If pg_tablespace and the
> symlinks can get out of sync, as you say below, why is pg_tablespace
> considered the authority? Or to put it another way, why not just
> look at the symlinks as in 9.2+?

Uh, good question.  I think I used the system tables because they were
easier to access.  I can't remember if we used the symlinks for some
things and pg_tablespace for other things in pre-9.2.