Allow me to join in on the Hibernate part of this discussion. I Agree on the performance issue by always requiring the insrel table. When you actually develop application with MMBase, you tend to program to the cloud-API, not use the taglib.
The common problems I encounter: - No foreign keys (since everything is in related using insrel, the database cannot check key constraints properly). - Performance is bad with queries over mulitple relations - No mapping to POJO's This means that you have to call 'node.getStringValue() etc.' methods all the time, can make errors in names of fields (going unnoticed for a long time, given the 'nice' default values instead of exceptions) On mapping a cloud with Hibernate: I considered writing a MMBase dialect for Hibernate that would support the insrel for one-to-many relations, allowing a POJO mapping to be used together with the regular cloud. Should be possible I think, don't have enough spare time to do it though.... Also, performance would still be bad using the insrel for every relation, but maybe Hibernate's second level cache can help here a bit (like the current querycaches). Edwin van der Elst -----Oorspronkelijk bericht----- Van: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Ernst Bunders Verzonden: vrijdag 12 mei 2006 12:04 Aan: Discussion list for developers Onderwerp: Re: [Developers] MMBase 1.8.1, 1.9.0 and beyond [cut] I think the point is that mmbase is allways using a join table (ei the relation) to join twoo nodes. That is not good for performance. Wat is really bad is if the same join table is used to join say 5 or 6 steps in one query. mmbase knows no other way. Specially when you combine this with crappy database inheritance, the insrel table becomes a problem.. Ernst -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.392 / Virus Database: 268.5.6/337 - Release Date: 11-5-2006 _______________________________________________ Developers mailing list [email protected] http://lists.mmbase.org/mailman/listinfo/developers
