Re: Two meanings of "data structures"

From: Kenneth Downs <firstinit.lastname_at_lastnameplusfam.net>
Date: Tue, 16 Nov 2004 23:23:29 -0500
Message-ID: <1b0r62-hco.ln1@pluto.downsfam.net>

Marshall Spight wrote:

> "Kenneth Downs" <firstinit.lastname_at_lastnameplusfam.net> wrote in message
> news:8oik62-3vd.ln1_at_pluto.downsfam.net...

>> I wonder if the literature has any well-known or popularly accepted works
>> that map the data structures that we learn about in coding classes --
>> those being arrays, linked lists, hash tables and so forth -- to the
>> relational model.
>>
>> By this I do not mean books that explain techniques in one or the other,
>> there are plenty of those, but rather something that provides a mapping
>> between them.  More specifically, the modelling of lists and arrays and
>> such in RDM.

>
> This is not an answer to your question, but I've wondered about
> a similar question. In Java, for example, one models everything with
> objects, and one has pre-built objects that model various generic
> data structures. If one wants a linked list, one uses
> java.util.LinkedList, etc. etc. In contrast, with RDM, one has to know how
> to model, for example, a tree with an adjacency list, or with a
> materialized path, etc.

If one wants a linked list in Java, one uses Perl :)

But seriously, I've been compiling my own maps of these, such as when you need an array, when a list, etc. The danger with this, and the reason for my post, is the fear of developing a lot of my own terms when others are in general use abroad.

I think Perl's hippie-free-love attitude does reveal how few structures there really are. You either point to something with an index or a name, and any thing can be an atomic value or another bag of things. Order is there but you can ignore it if is irrelevant, or change it.

SQL lacks a simple way to turn its native son, the table, into a list, something like the Join() function. It likewise lacks the Split(). Most procedural environments except for the may-as-well-be-dead Visual Foxpro lack any way to deal with tables intelligently.

>
> What I wonder about is, is there a way to achieve the drop-in property
> that OO gives you with RDM? It doesn't seem obvious how one
> would do that.
>

>
> Marshall

-- 
Kenneth Downs

java.lang.String.tcpip.usenet.content.posting.sigblock.setSig("After finally
finding the right object and method to set the sig block, I forgot what I
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Received on Tue Nov 16 2004 - 22:23:29 CST