On Oct21, 2011, at 19:47 , Robert Haas wrote: > On Fri, Oct 21, 2011 at 1:40 PM, Florian Pflug <f...@phlo.org> wrote: >> AFAIR, the performance hit we'd take by making the vacuum cutoff point >> (i.e. GetOldestXmin()) global instead of database-local has been repeatedly >> used in the past as an against against cross-database queries. I have to >> admit that I currently cannot seem to find an entry in the archives to >> back that up, though.
> I haven't seen anyone explain why they really need this feature > anyway, and I think it's going in the wrong direction. IMHO, anyone > who wants to be doing cross-database queries should be using schemas > instead, and if that's not workable for some reason, then we should > improve the schema implementation until it becomes workable. I think > that the target use case for separate databases ought to be > multi-tenancy, but what is needed there is actually more isolation > (e.g. wrt/role names, cluster-wide visibility of pg_database contents, > etc.), not less. Agreed. I wasn't trying to argue for cross-database queries - quite the opposite, actually. My point was more that since we've used database isolation as an argument against cross-database queries in the past, we shouldn't sacrifice it now for synchronized snapshots. best regards, Florian Pflug -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers