On Fri, Jun 30, 2006 at 05:55:53PM -0700, Tracy R Reed wrote: > > Neat idea but as this guy points out it is hard to make these two > different ways of design and thinking (relational vs object) mesh > nicely. This is one reason why I have been studying ZODB. > > http://blogs.tedneward.com/PermaLink,guid,33e0e84c-1a82-4362-bb15-eb18a1a1d91f.aspx > > His Vietnam analogy is quite strained but after that he gets into good > details about the difficulties.
I generally find ORMs rather disappointing. They are either featureful and slow (hibernate, sqlalchemy) or they just get in the way of making full use of the sql engine (SQLObject). I find that it's usually efficacious to just do a straight sql call for reports (like a big master list) and instantiate objects as needed (e.g. for a detail form.) ZODB is great if startup time is not a big factor. In particular, if you have to traverse a big object graph because you need to sort it first, it can be quite costly (the same issue that the ORMs have, I guess, but you don't have the option of going directly to a relational engine to get around it). Once your objects are loaded into memory it's pretty fast. With an OODB you'll have to do all the indexing and integrity checks yourself. There's a new Berkeley DB backend for the Durus OODB that claims to have a fast startup time, but I haven't had a chance to try it: http://www.argo.es/~jcea/programacion/durus-berkeleydbstorage.htm You might also want to check out buzhug, but it also has the same startup time issue. Dave -- [email protected] http://www.kernel-panic.org/cgi-bin/mailman/listinfo/kplug-lpsg
