That, really, is the bugbear I should have been talking about a couple of years ago. It's not some vague "databases aren't fast enough" problem, it's "collecting a tree of objects, each of which is also in an inheritance tree, is slow." Individual objects are no big deal... definitely a solved problem. A collection of objects in a language with limited run-time reflection, on the other hand...
I had hoped that Agile Database Techniques would address these larger-scale object/relational mapping problems, but unfortunately it has not. It appears very much targeted at the enterprise software market (one where, in my opinion, "agile" is relative), and avoids (predates?) the web-oriented agile development community (where I have also been looking, to some extent).
So, it is a decent read, and puts in one place a lot of information on iterative database development in enough depth that you can connect the dots and do it yourself (e.g., test-driven development is a perfectly valid strategy for database schema design too). Not so awesome if you're not a DBA, not working in enterprise software, or dealing with the particular problems of games, but still a decent read. At $26 from Amazon, it may be worth putting on your bookshelf... as long as your expectations are reasonable. :)
