I've had some pushback from Felix over my relational databases aren't dead yet post. He points to db4o.

Now, I've not used db4o, but I've tried out ZODB, and very good it is too. especially with a dynamic language it's really nice to be able to tag arbitrary attributes onto your objects, and to be able to persist and retrieve them complete.

But still, I've be wary of using one for a real project. Performance aside, there are things that you just can't do as easily with an ODBMS as with an RDBMS. I'm thinking of things like:

• Report writing
• Data loading
• Data exploration (especially during debugging)

Also, I find it hard to imagine that an ODBMS can be optimized to the same extent as something as notionally simple as a relational database can be.

All this is leaving aside things that don't yet exist AFAIK but which are probably just a small matter of programming - management tools, clustering, that kind of thing.

No, I'll be sticking with the RDBMS for the foreseeable.