> -----Oorspronkelijk bericht----- > Van: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Namens Michiel Meeuwissen > Verzonden: woensdag 14 september 2005 11:24 > Aan: Discussion list for developers > Onderwerp: Re: [Developers] table inheritance on relations in mmbase > > > Ernst Bunders wrote: > > hello > > while doing some optimizations on hour database we ren into an > > interesting question. we are using postgres, and table inheritance > > works as such that when we have a query like people,insrel,articles > > and we have relations like posrel and publishrel extending from > > insrel, all these tables are searched as well. I don't > think this is > > the kind of behavour you want for relations. why search > through posrel > > if we are looking for an insrel? With ordinary nodes it is > different: > > if we have 'interview' extending from 'article' and we wat all > > articles, we indeed want all interviews as well. > > So it would seem that we don't want table inheritance on > relations, and > > performance might in fact increase dramatically in large > clouds if we > > could drop it. Am i wrong? Do tell.. > > I think we should perhaps not drop inheritance, because that > makes listing of related nodes withouth a specification of > the 'role' work. > > What we perhaps should do though, is that it should be > possible that if a role exists only on 'insrel', and that the > database is postgresql that it produces the right keyword in > the sql-query to search only in that table (I think it is > 'ONLY' or so)? So, it would be a postgresql-specific > query-optimization.
i will experiment with the ONLY keyword ernst > > For databases in which we only simulate inheritance (like > mysql) this is no issue. > > > Michiel > > > -- > Michiel Meeuwissen mihxil' > Peperbus 111 MediaPark H'sum [] () > +31 (0)35 6772979 nl_NL eo_XX en_US > > > > _______________________________________________ > Developers mailing list > [email protected] > http://lists.mmbase.org/mailman/listinfo/developers > _______________________________________________ Developers mailing list [email protected] http://lists.mmbase.org/mailman/listinfo/developers
