Alvaro Herrera <alvhe...@commandprompt.com> writes: > Dimitri Fontaine escribió: >> Why can't MVCC apply here? You'd have two versions of the pg_class entry >> that just has been CLUSTERed, and you keep the old relfilenode arround >> too. MVCC applies, and you teach vacuum to clean out the old file when >> cleaning out the no more visible tuple. > > It just doesn't work. pg_class (and various other rels) are special > because they are needed to bootstrap the catalog system. See > RelationCacheInitializePhase3. It wouldn't be possible to figure out > what's pg_class relfilenode until you have read it from pg_class, which > is precisely what we're trying to do.
Well at bootstrap time I guess noone is able to disturb the system by placing a concurrent CLUSTER pg_class; call. Once started, do those rels still need to have a special behavior? I guess I'm being dense, will now let people in the know find a solution... -- dim -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
