On Wed, Jan 28, 2009 at 5:00 PM, Zdenek Kotala <zdenek.kot...@sun.com> wrote: > Tom Lane píše v st 28. 01. 2009 v 14:06 -0500: >> Trying to do catalog upgrade >> in-place is going to be a complete mess. I'd be interested to know, >> for example, how you imagine rearranging the contents of pg_class would >> work. You don't get to modify pg_class if you can't even find it, which >> you can't because you can't read it. > > It is relatively easy. There are very high design: > > 1) upgrade move old catalog table into save location. We can create for > example special tablespace for it > > 2) bootstrap creates catalog + create records for old catalog structure > > 3) data will be copied like > > INSERT INTO pg_class select from pg_upgrade.pg_class where oid>16... > > In reality it will be more complicated command but pure SQL.
I really like this idea, assuming I understand it. Basically, I think you're proposing that we move the old system catalogs out of the way, bootstrap a new catalog, and then using SQL (running inside a standalone backend?) to migrate data from the old catalog to the new one. That sounds really good to me. Even a relatively complicated catalog reorganization should be able to be handled this way without too much work or a lot of special-purpose code. ...Robert -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
