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Re: retrieve rows in a specified order

From: Paul <paul_at_not.a.chance.ie>
Date: Mon, 22 Dec 2003 00:04:50 -0000
Message-ID: <MPG.1a504579bf1ce789989856@news1.eircom.net>

mspight_at_dnai.com says...

> > At least that's my understanding of one of the reasons why the concept
> > of row number is out for RDBMS's - anyone disagree?
 

> My thoughts on why no row order:
 

> 1) Relations are based on set theory. Members in sets are unordered.
 

> 2) Adding implicit ordering information would give you nothing
> that you don't already have with explicit ordering. Except implicit
> ordering would require a bunch of new operations, like the aforementioned
> MOVE UP, MOVE DOWN, etc. That is, it would add complexity but
> no power.

Maybe I'm wrong here, but have you mixed up "implicit" and "explicit" in this paragraph?

Adding *_explicit_* (i.e. by row) ordering would give you nothing that you don't already have with *_implicit_* (i.e. by key or given field name) ordering. Except *_explicit_* (row) ordering would require a bunch of new operations...

Paul...

> Marshall

-- 

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Received on Sun Dec 21 2003 - 18:04:50 CST

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