Anyone who is deeply enmeshed in a technology feels compelled to defend that technology when any sort of "threat" (or perception of threat) appears on the horizon, and apparently Gavin is no different. Sure enough, as people (apparently in this case, myself) start to talk about approaches to persistence that don't involve Hibernate, Gavin feels compelled to point to these other technologies using inflammatory terms and a certain amount of FUD. I felt a certain responsibility to respond, since it seems that he's taking a direct shot at the db4o articles I've written and discussed before. (By the way, it's also entirely possible that he's taking aim against ActiveRecord and Rails, which I don't consider to be an "object database" at all; if that's the case, then I apologize ahead of time for misunderstanding the intent--and the points--of the piece. But the arguments he makes seem pretty relevant to the OODBMS-vs-RDBMS discusison as well, so much so that it was a db4o employee who pointed out the blog entry to me in the first place. In any event, though, Gavin's piece raises some issues that deserve to be discussed, regardless of the context of Rails or OODBMSs.) First of all, let me state quite clearly, the relational database needs no defense . Take whatever comparitive criteria you like, the RDBMS has been, and will, in the absence of a nearly catastrophic change to the contrary, continue to be, the choice of businesses all over the world for storing data in a format that's easily-accessed from a variety of different systems. The RDBMS clearly "owns" the corporate data center, from Fortune X's (meaning X can be just about any number you choose to put there) down through single-person shops. To shake that kind of (dare I say it?) monopoly would require a kind of technology shift on the scale of the move from the mini- and mainframe to the PC. Those kinds of shifts don't happen very often, and when they do, it's because of a huge competitive advantage. Furthermore, I wil go on the record and say it here: neither the OODBMS nor the HODBMS (hierarchically-oriented database system, a la the "XML database") makes that kind of case. Not right now, and probably not ever. They have compelling reasons for existence, but not so strong a case that they could displace the RDBMS from the "enterprise data" throne. That said, however, since when does one tool solve all problems? They have their own raisons d'etre , and to simply say that the OODBMS or HODBMS should be ignored Read More...