Chris Date is quite annoyed with me, and has taken issue with various things I’ve written. Some of his reasoning is hard to follow. For example, he said something to the effect that it would be silly for him to ever say anything misleading, because he’d immediately be caught out. Uh, Chris – you’re the guy who’s berating the terrible level of education and understanding in a field for which YOU WROTE THE DEFINITIVE TEXTBOOK (which has sold “over 700,000 copies”). If your readers can’t even understand the correct things you say in your book, why should they be able to instantly spot the errors?
Even odder is Date’s multi-paragraph diatribe about a specific two-word phrase I supposedly used. Maybe if he’d looked and read what I’d really said, it would have made more sense to him. Or maybe not. He also bragged about not knowing who I am, thus revealing a couple of things. First, he can’t be bothered to use Google any more than he can be to actually read a blog post he’s criticizing. Second, he’s pretty out of touch with the actual DBMS industry, something which can be independently inferred from his frequently bizarre statements about DBMS vendors and their technology. (Chris Date may still be one of the world’s great experts on the use of DBMS, but when it comes to actually building them, he seems to be pathetically ignorant.)
Other things he says in that piece, however, are sufficiently coherent to warrant an attempt at response. So here goes.
He starts by asking, in effect, “Why are you picking on me?” Well, I didn’t start out by intending to pick on Chris Date. But Fabian Pascal engaged me in flaming discussion, and when he found himself out of his depth, quickly resorted to what he seemingly thought was a discussion-ender, namely dropping the sanctified name of “Chris Date.” So I did a little poking around, and discovered that Date indeed has explicitly endorsed Pascal and Pascal’s website, posts on Pascal’s website “on a fairly regular basis,” lets Pascal speak for him, and generally seems in my opinion to be responsible for and indeed to apparently agree with the views Pascal ascribes to him.
Beyond that, I’m picking on Date because he is misleading his paying audience(s) on the subject of TransRelational technology. In that regard he’s acting like so many other DBMS vendor marketing spokespeople, who may not have been precisely lying, in that they probably deluded themselves before peddling nonsense to others. But at least John Cullinane and Dave Peterschmidt were shipping actual, useful products. Nor did they charge for seminar admittances or book sales just so that people could hear their pitches.
Moving on, Date claims that his views are scientific in general nature. However, he ignores overwhelming evidence against them, namely the last 20 years of development and use of relational DBMS, and presents almost no empirical evidence for them. So yes, I stand by my claim that the pure-relational fanatics are “reasoning” in a quasi-religious manner much more than they are reasoning scientifically (in any sense of “science”).
This ties into the claims that to be against relational theory is to be against logic, that relational theory is based on science that was established over 2,000 years ago, and so on. The most outrageous versions I’ve seen of such hokum indeed came from Pascal’s keyboard rather than Date’s. But as noted above, Chris Date supports Fabian Pascal, and anyhow what Date himself says is bad enough.
About the most expansive valid claim that can be made along those lines is “Sound mathematical predictions can be made about the behavior of systems built in conformance to the Relational Model, and the same is not at this time equally true of systems that do not conform to the RM. In particular, it is possible to make mathematically sound assurances about data integrity.” That’s a strong argument for using the RM in certain contexts – quite a few contexts, actually. But it hardly refutes the central claims of the DBMS2 agenda, nor is it a strong argument against the use of today’s SQL-oriented DBMS. And it certainly doesn’t excuse the bitter insults Date and Pascal regularly hurl at both the DBMS user and DBMS developer communities. Nor does it justify their vitriolic attacks on me. Nor does it support many other things that Date and/or Pascal have said.
I think this covers most of what Date said in his screed. Oh, he had a lot more numbered points than that, but they seemed to repeatedly touch on the issues mentioned above. As for the less personal, and much more important, aspects of our disagreement – well, this whole blog repeatedly covers those subjects.
Finally, a bit of self-examination here – is my disagreement with Date really that important, or am I like Captain Queeg with the missing strawberries, trying to reenact the successes of my younger years (e.g., Cullinet and Sybase)? Well, Required Technologies surely is not an important target – but nor have I focused on it. My real target is any claim that a large enterprise should obsessively try to run itself on One Grand Centralized relational database (especially one that actually ships commercially; I’ve been assuming that no enterprise would try to bet the farm on an idealized “true relational” product that lacks the key buying criterion of “it actually exists.”). It just so happens that the shrillest initial opposition to this idea came from Chris Date’s spokesman Fabian Pascal, and it’s Pascal who brought Date into the conversation.