Re: 1GB Tables as Classes, or Tables as Types, and all that refuted

"Alfredo Novoa" <anovoa_at_ncs.es> wrote in message news:8v3nr0lcv0jr6sqpqvp10keq4eeuhggji5_at_4ax.com...
> On Fri, 10 Dec 2004 18:26:25 -0600, "Dawn M. Wolthuis"
> <dwolt_at_tincat-group.comREMOVE> wrote:
>
>>Name one precise problem that the hierarchical DBMS's had that is now
>>present for anyone using an XML model of data.
>
> The horrendous complexity and inflexibility.

For example ... ?

>> It's time to drop the flawed
>>notion that data graphs have some inherent problems.
>
> Graph based data models have severe inherent problems.

Another fine arguement, start to finish ;-)

>> One can build terrible
>>database management systems based on graphs or good ones. The model,
>>itself, is useful and never was abandoned in reality (or in Reality, a
>>database from the company Northgate -- McDonnell-Douglas and variants of
>>the
>>company kept this graph-based solution active since the early 70's as the
>>Microdata company, and it is still being sold and used today)
>
> Many roman bridges are being used today, but it does not mean that we
> should build bridges in the same way as in the I century.

Agreed. I'm not suggesting using old engineering techniques simply because they worked. There might be better approaches to be sure.

>>Graph-based data models have survived the Relational Database trend and
>>will
>>now get a new push given that more people now understand -- and even more
>>will! -- that RDBMS's have no better theorectical basis than graph-based
>>database management tools.
>
> You are playing with words again. Graph theory is not better or worse
> than predicate logic or differential calculus,

WE AGREE -- WE AGREE!! but the Relational
> Model is dramatically superior to the graph based data models.

Are you certain this not a religious belief rather than a clearly reasoned conclusion? I have not yet found the convincing reason in the literature nor in my experience.

The relational model has its charm in using sets as do graph-based models in traversing paths (the day I have to think in terms of set theory to zero in on a document that I could navigate to in a folder structure ...)

When modeling language (in a quite simplified version) as we do with modeling propositions/predicates, reasons for choosing one modeling approach over another might be

1. if there are problems retrieving the data one wants with one or the other approach
2. if there are performance issues with every implementation of one model that do not show up in the other
3. if it is conceptually easier making for "agile" software development and/or maintenance.

My experience (compared to a logical conclusion from a set of axioms) is that querying is easier (at least not harder) with graphs, performance is better (or at least not worse) and it is often conceptually easier, lending itself to more agile (sorry for the use of that word -- I used to like it) development and maintenance using graph models for your everyday "data processing" concerns. I've found no solid logic nor empirical data to say otherwise -- have you?
--dawn

>
> Regards
>
Received on Sun Dec 12 2004 - 02:40:28 CET