Re: Is mysql a RDBMS ?

On Mon, 25 Aug 2003 11:57:09 -0700, Mikito Harakiri wrote:

> if relational theory would
> comprise all the math, not predicate calculus only.

        But why would one want that?

        BTW, the relational model is based on set theory (hence relational) and predicate *logic*. It can make use of either relational algebra, or relational calculus, or both.

> For example, how would
> you represent multivariate polynomial
>
> 3*x*y^2+5*x^3
>
> relationally?

        Again, why would one want that?

> Difference between pure Relational and SQL are well known and in my opinion
> are negligeble compared to huge gaps in relational theory.

        Your opinion is irrelevant without a justification.

> The examples of
> (still) open research topics include view updates

        Nice of you to ignore the nicest view updateability model proposed by D&D... or even worse, about thinking the difference between their model and the angelic space is more important than the one between their model and SQL! The thing is, we're stuck with SQL for now while there is a much better model available, and only one or two small-time vendors striving for it. That it is not perfect is the irrelevant issue here.

> transitive closure

        What's missing?

> optimization

        D&D and others have again and again shewn that the relational model is much more optimisable than SQL... we don't even need them telling us so, as everyone who've used SQL is familiar with its arbitrary restrictions, lack of logic etc that have a negative impact on optmisation.

> multidimensional methods

        I'm not sure what do you mean, but it seems this is irrelevant to RDBMSs and the model, being more on the application level.

> constraint databases

        What's the problem here? Again not sure of your meaning, but the relational models have a complete declarative integrity constraints system.

> etc, etc.

        What's that?

> "Pure" relational language is not going to solve those by "magic".

        Who wants magic? Logic is the thing.

        BTW, why "pure" in double quotes? I sense some misplaced irony here. SQL is not only 'impure', it is not relational at all.

> I would think reiterating SQL and Relational diferences over and
> over again is just counter productive.

        Actually, proposing SQL as relational is counter productive. Pointing it isn't is educational.

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