Re: Pizza Example

From: Anthony W. Youngman <>
Date: Thu, 15 Apr 2004 22:11:36 +0100
Message-ID: <ym$>

In message <HLyec.53517$>, Eric Kaun <> writes
>> I want my cake and eat it too! The PICK structure does what I have
>> described and is "amenable to automated deduction" and it seems to me that
>> there is some value in that, but I'm still poking and prodding to clarify
>> what that might be.
>Of course it's amenable, just much less so. It's its lack of symmetry and
>consistency that poses a problem. By nesting values inside values (and then
>a further layer inside that, I believe), you complicate the algebras,
>closure, and optimizations. Relational is much simpler, hence its power.

Define "simple".

So if I run a query, that gives me a view of a complex object, why does it give me an indeterminate number of copies of a piece of data that is stored just once?

Or, I want to find all the attributes of a single, real-world object. With relational, that's a complex query. With Pick, it's "here's the (singular) primary key, get the data".

As I said, define "simple" :-)

As for saying "it complicates the algebra...", WHY? It makes it easier to do stupid things, but it doesn't affect the algebra and, indeed, despite making it easier to be stupid, in practice it seems to make it less common.


Anthony W. Youngman - wol at thewolery dot demon dot co dot uk
HEX wondered how much he should tell the Wizards. He felt it would not be a
good idea to burden them with too much input. Hex always thought of his reports
as Lies-to-People.
The Science of Discworld : (c) Terry Pratchett 1999
Received on Thu Apr 15 2004 - 23:11:36 CEST

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