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Re: Pizza Example

From: Eric Kaun <ekaun_at_yahoo.com>
Date: Fri, 23 Apr 2004 18:09:04 GMT
Message-ID: <4Zcic.11391$Jr5.8164@newssvr31.news.prodigy.com>


"Anthony W. Youngman" <wol_at_thewolery.demon.co.uk> wrote in message news:irwPxZDNZwhAFwVT_at_thewolery.demon.co.uk...
> As I understand it (I may well be wrong), most queries in a relational
> database are complicated/difficult because of joins.

Joins don't make things difficult, in general. In SQL they're far more convoluted than in a general relational algebra, but given the procedural code I've seen even in Java, complexity isn't the issue. I think programmers are just indoctrinated in procedural methods, rather than declarative ones.

> Viewed from a Pick
> mindset, the typical reaction is "what do you want a join for?". Pick
> doesn't have joins in the relational sense because it just doesn't make
> sense in the Pick world-view.

Sure it does. You never have the need to query for information that crosses over several files? You're doing a join - you're just doing it laboriously and procedurally.

> A bit like the Feynman story about calculus - Dick was taught an unusual
> technique and all his colleagues thought he was calculus genius. But as
> he said, they gave him all the problems they thought difficult, and with
> his different toolset he solved them easily. But if they'd given him the
> problems they thought easy, he would have been stumped.

Possibly, but we're not talking about individual problem solving, at least not all the time. We're talking about information structures for a business. And if you have multiple data models, you're going to have mapping problems, probably severe ones. At some point the business has to (or should!) define what it means by its data, and it's better to do that in one way, unless you can very carefully identify non-overlapping domains which have a need for different paradigms. I've never seen such a thing, but that doesn't mean the black swan doesn't exist.

> As for the difficult queries, with its different toolkit, would Pick
> think them difficult? If you could give me an example of a "difficult"
> query, I would be able to comment. Being a text-based system, Pick
> *ought* to be a good match.

How does being text-based help that?

Anyway, certainly you have cases where you need to combine information from several files. How do you do it?

> I got the source of wikipedia on a cover disk this month :-) so I may
> well take a look at it. Only snag is, "I don't do Perl", which is I
> believe the language it's written in. But I ought to look at stuff like
> that :-)

Perl is heinous, or at least (like C++) tacitly encourages heinous practices. It can do a lot, but well, so can assembler.

Received on Fri Apr 23 2004 - 13:09:04 CDT

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