Re: The IDS, the EDS and the DBMS

Alfredo Novoa wrote:

> mAsterdam wrote:
>

>>Why are these object-relational mapping projects bogus?
>>Is it because bridging the impedance mismatch is not a
>>worthwhile quest, is it because it it impossible or
>>just because none of these projects has done a good
>>job at it yet?

The patient being?
The disease being?
Let's try to properly pin-point the problems and the stuff we'ld like to save.

> The solution is to include relation variables and the relational
> algebra/calculus in the application languages and not to hide the
> declarative set oriented DBMS behind a procedural record oriented
> layer.

That would indeed be nice to have.
ISTM that is one way of trying to do object-relational mapping. Maybe tha best - but we can only find out after we have a common vocabulary to discuss and evaluate the alternatives.

>>That the the kinds of queries you can make are limited
>>by these projects is evident; their single
>>purpose is to hide complexity from you.

I'll try translating this into a less relational *versus* object version:
One thing the projects should not try to hide in hiding the complexity is the ease of operating at set-level. Another no-hide thing is the power of declarative languages. Am I understanding you correctly (for now dodging the implications)?

>>Trade offs are to be expected.

Yes. One nuance: Code is used more often than it is written, so in widely used systems a part of this cost dissappears. The performance hit stays, evidently.

>>However, if the relational interface
>>is of just the right complexity, every
>>encapsulating effort is futile, every
>>limit cripples.

While this does express your attitude,
it does not explain why (or where) the
relational interface would be
of just the right complexity.

I think data sharing is not and should not be the privilege of people with a sound knowledge of "The Relational Model" (capitalization yours). Received on Sun Sep 05 2004 - 12:19:06 CEST