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Re: To Null or not to Null. That is the question!

Dear Mr Darwen: The only perjorative in my intent was against those who have come to think the SQL is a good example of the relational model! That is, I used the word "purist" to avoid confusion with the popular misunderstanding of "relational". I bet you get very tired of being drawn...

Posted to Conceptual modeling (Forum) by Clifford Heath on 05-25-2011
Re: To Null or not to Null. That is the question!

[quote user="hughdarwen"]performance is a characteristic of the implementation, not the language[/quote] While it's all very well to claim that, real applications must be written with real DBMS. [quote user="hughdarwen"]some queries of course go faster after decomposition[/quote...

Posted to Conceptual modeling (Forum) by Clifford Heath on 05-22-2011
ActiveFacts and CQL

ActiveFacts is a free open-source project of Data Constellation which implements the Constellation Query Language (CQL) and the Constellation API. The Constellation Query Language was presented at the ORM Workshop 2009 in Portugal, and a version of that presentation is available in a screencast you can...

Posted to ActiveFacts (Forum) by Clifford Heath on 05-19-2010
Re: Model THIS!

[quote user="OrionB"]I would have found it quicker and easier to read a diagram[/quote] Certainly - the natural language and diagrams are both necessary adjuncts. CQL is aimed at improving collaboration of the kind you note, but plain text has other advantages too. It is easy to write and ship...

Posted to Request a topic (Forum) by Clifford Heath on 05-10-2010
Re: Model THIS!

Alright, I gave it a go, in CQL. Note: this uses features of CQL that aren't yet released, and even a couple that aren't yet implemented . I didn't produce the derivation for the grand prize, but a derivation for the first three prizes for each event is given (if there's an equal first...

Posted to Request a topic (Forum) by Clifford Heath on 05-10-2010
Re: ORM2 Exchange Language

[quote user="Clifford Heath"]So far as I've seen, every attempt at collaboration to construct a meta-model has failed to even get started. I got so frustrated that I built my own, more than a year ago, and despite some early and very helpful feedback, have had no indications that anyone...

Posted to Other Tools (Forum) by Ken Evans on 01-12-2009
Re: ORM2 Exchange Language

[quote user="Clifford Heath"]A model converted from NORMA to CQL takes almost exactly the same amount of paper to print [/quote] Hi Clifford, thanks for your observation about paper volumes. However, it seems to me that the "volume of paper" argument is a different issue. I don't...

Posted to Other Tools (Forum) by Ken Evans on 01-12-2009
Re: ORM2 Exchange Language

Jakob, BrianC (and others), My ActiveFacts project has produced: A metamodel in ORM2 which is capable of fully(*) representing ORM2 (and more - like units support, multiple overlapping models, multiple natural languages for the same model, reference populations as well as an example one, join constraints...

Posted to Other Tools (Forum) by Clifford Heath on 01-11-2009
Re: A new tool, the Constellation Query Language

CQL for your caller preferences model follows. It lacks subtype exclusion between the CommunicationPath subtypes, by the way. The uniqueness constraints at the end of the file would have been embedded in a reading in the fact type definition, if a reading in the correct role order was provided. This...

Posted to Other Tools (Forum) by Clifford Heath on 08-27-2008
Re: A new tool, the Constellation Query Language

Hi Clifford, I forgot to mention this earlier, but .orm (nORMa tool files), uploaded to the Library section here, ought to make good test fodder for your converter (as in the model fragment I uploaded about caller preferences: http://www.ormfoundation.org/files/folders/norma/entry1191.aspx ) Posting...

Posted to Other Tools (Forum) by Brian Nalewajek on 08-26-2008

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