Re: Reminder, blatant ad

From: dawn <dawnwolthuis_at_gmail.com>
Date: 9 Feb 2006 14:27:33 -0800
Message-ID: <1139524053.201773.106400_at_g14g2000cwa.googlegroups.com>


Jan Hidders wrote:
> dawn wrote:
> >
> > [...] If you were writing
> > a "data processing 101" type of application, such as a "Pet Store" app
> > (if you are familiar with the Java and other Pet Store examples) or the
> > Joke Response System described on my web site
> > http://www.tincat-group.com/swdev/jokesreq.html and you had complete
> > freedom in tool and standards selections, would you be more likely to
> > choose a Relational Model to work with your DBMS or an "XML data model"
> > or other model that includes attributes with list values?
>
> For the Joke Response System I would choose RM-oriented tools, as I
> don't think that the data and the associated access patterns are
> evidently hierarchically organized.

That's what I suspected. I would use a web-like model with a di-graph of little trees.

>
> > Additionally, if you chose a SQL-DBMS tool for practical purposes such
> > as wide-spread use and availability, is there something lacking from
> > current tools that use alternative data models (e.g. XML database,
> > Cache', PICK databases such as IBM U2, Berkeley-DB,...) that would
> > cause you to reconsider if such features magically appeared?
>
> Hmmm, data independence would be an important factor.

I'd like to better understand data independence in terms of functionality.

Does it mean that if a new version of a DBMS tool takes the same logical specification it can lay the bytes down differently on the disk without application code changing? In that case, I'm pretty sure most DBMS tools, including MUMPS and PICK, fit the bill.

Or does the decoupling of physical and logical mean that if I want to store attribute data physically "along with" a different entity (table) than where it is now (and rework the logical model), no application software needs to change? Using a SQL-DBMS, that would mean no data should be accessed through a base table, only through derived views. In that case, no dbms enforces such and I don't know if there are software applications that function that way.

I'm likely confused on this topic as I have not studied it in depth. Thanks in advance. --dawn Received on Thu Feb 09 2006 - 23:27:33 CET

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