Itagaki Takahiro wrote: > We still need traditional VACUUM FULL behavior for system catalog because > we cannot change relfilenode for them. Also, VACUUM FULL REPLACE is not > always better than traditional VACUUM FULL; the new version requires > additional disk space and might be slower if we have a few dead tuples.
Tom was saying that we could fix the problem that relfilenode could not be changed by having a flat file filenode map. It would only be needed for nailed system catalogs (the rest of the tables grab their relfilenode from pg_class as usual) so it wouldn't have the problems that the previous flatfiles had (which was that they could grow too much). I don't recall if this got implemented (I don't think it did). As for it being slower with few dead tuples, I don't think this is a problem -- just use lazy vacuum in that case. I also remember we agreed on something about the need for extra disk space, but I can't remember what it was. -- Alvaro Herrera http://www.CommandPrompt.com/ The PostgreSQL Company - Command Prompt, Inc. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
