Re: [seweb-list] A Comparison of RDF Query Languages

The proper response to your request is obvious in
your report.

 > Related to the recent work of the RDF Data Access
 > Working Group [1], we have compared six proposals
 > for RDF query languages. The report, the use case
 > data, and the queries are available online [2].
 > Looking forward to hearing your feedback.

There is only one language that has YES marks for
every category in the evaluation matrix -- and that
is controlled English (or a similarly restricted
version of any other natural language).

At the end of this note are the 14 evaluation questions,
which are stated in an easily processable version of
controlled English.  That notation is the obvious
query language for the semantic web (or any other
system that claims to be "semantic").  All the other
proposals, which failed to satisfy 3 or more of
the requirements, should be treated as inadequate
attempts to optimize the language for the benefit
of the machine rather than the human users.

Anybody who fails to understand this point should
be condemned to reread the debates on database
languages between Ted Codd and Charlie Bachman
from 30 years ago.

John Sowa

    A Comparions of RDF Query languages

The 14 queries as stated in that report:

1 Path Expression
Return the names of the authors of publication X.

2 Optional Path
Return the name and, if known, the e-mail of the author of publication X.

3 union
Return the labels of all topics and (union) the titles of all publications.

4 difference
Return the labels of all topics that are not titles of publications.

5 Quantification
Return the persons who are authors of all publications.

6 Aggregation
Count the number of authors of a publication.

7 Recursion
Return all subtopics of topic "Information Systems", recursively.

8 Reification
Return the person who has classified the publication X.

9 Collections and Containers
Return the first author of Publication X.

10 Namespace
Return all resources whose namespace starts with 

11 Language
Return the German label of the topic whose English label is "Database 

12 Lexical Space
Return all publications where the page number is the lexical value '08'.

13 Value Space
Return all publications where the page number is the integer value 8.

14 Entailment
Return all instances that are members of the class Publication.

Received on Sunday, 2 May 2004 12:10:50 UTC