[sc34wg3] TMQL, State of Affairs

Jan Algermissen sc34wg3@isotopicmaps.org
Mon, 23 May 2005 22:32:54 +0200

On May 23, 2005, at 10:21 PM, Martin Bryan wrote:

>  why yet another query language is needed, and why XQuery or
> somehting based on the tried and tested ISO-standardized SQL  
> approach would
> not do just as well.

Hi Martin,

a query language is neccessarily defined in terms of an underlying  
data model (data model in
the sense that the relational model is a data model and not in the  
sense 'domain model').

Xquery is based on the DOM (XML heads correct me please), SQL is  
based on the relational model
(on relational calculus and relational algebra).

Topic Maps [1] are a completely different data model so you need a  
new query language.


[1] TMDM (part of it) definitely is a data model and IMHO the RM has  
allways been one, too
     (though the current authors disagree with me on this).