Re: retrieve rows in a specified order
Date: Mon, 22 Dec 2003 00:04:50 -0000
Message-ID: <MPG.1a504579bf1ce789989856_at_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
-- plinehan x__AT__x yahoo x__DOT__x com C++ Builder 5 SP1, Interbase 6.0.1.6 IBX 5.04 W2K Pro Please do not top-post.Received on Mon Dec 22 2003 - 01:04:50 CET