Re: By The Dawn's Normal Light

From: Paul <paul_at_test.com>
Date: Fri, 29 Oct 2004 16:05:33 +0100
Message-ID: <41825c43$0$4020$ed2619ec_at_ptn-nntp-reader01.plus.net>


Dawn M. Wolthuis wrote:

> Where ordered lists are not implemented, users place ordering attributes
> into the data.  The predicates stay the same whether a user adds in an
> ordering attribute or the dbms software handles the ordering attribute
> (along with inserts & deletes to an ordered list).  There is no change to
> predicates in this case.  --dawn

OK, so you mean lists would still be relations underneath, but the DBMS would provide some "syntactic sugar" for manipulating them as lists?

e.g. if you have a list done in a relation like this:

(A, 1)
(B, 2)

Then you want to add a value inbetween:

(A, 1)
(X, 15)
(B, 2)

and

(A, 1)
(B, 125)
(X, 15)
(B, 2)

then the additional operators will sort out the complicated queries
(which are certainly possible in SQL) like "what is the 3rd member of
the list?" or "return the list in order", "add a new value in 2nd place", etc. in a more user-friendly way?

Paul. Received on Fri Oct 29 2004 - 17:05:33 CEST

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