Re: Object-relational impedence

From: rpost <>
Date: Mon, 17 Mar 2008 19:12:35 +0100
Message-ID: <45d85$47deb493$839b4533$>

Marshall wrote:

>On Mar 15, 4:49 pm, (rpost) wrote:
>> Marshall wrote:
>> >The "vague collections" idea is not a good one IMHO.
>> >Because you can get more or less everything you want
>> >with relations. (Surprise! I like relations! :-)
>> But you often get more (e.g. you don't always need the
>> uniqueness of elements).
>There is really only one collection type where that is strictly
>true: bags. Bags seem to me to be the singularly least
>useful data structure I have encountered. Even so, they
>are acceptably encoded as relations over <element, count.>

Well, ordered lists are another, but they are only useful if no attribute can be modelled by which the ordering happens, and that is very rare; besides, they too can be expressed as relations, e.g. <element, nextelement> or <element, index>.

So I agree that not having them isn't so bad.

Received on Mon Mar 17 2008 - 19:12:35 CET

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