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Re: RDF query language

From: Eric Prud'hommeaux <eric@w3.org>
Date: Tue, 5 Feb 2002 16:42:01 -0500
To: Wolfgang Nejdl <nejdl@kbs.uni-hannover.de>
Cc: Libby Miller <Libby.Miller@bristol.ac.uk>, www-rdf-rules@w3.org, gt77@gmx.at
Message-ID: <20020205164201.A24619@w3.org>
On Thu, Jan 31, 2002 at 08:52:12PM +0100, Wolfgang Nejdl wrote:
> > 
> > I just sent this reply to the rdf interest group list: I thought it
> > might be worth posting it here as well, in case I've missed out lots of
> > systems or got the details wrong.
> > 
> 
> Edutella (edutella.jxta.org) includes a Query Exchange Language based
> on Datalog semantics, called RDF-QEL-i (it's actually a family of
> languages, but with one common semantics). It is described in a WWW'11
> paper (see http://edutella.jxta.org/reports/edutella-whitepaper.pdf
> for the preliminary version).

I'll add it to my survey or RDF query languages [1]. Perhaps you could
construct the query that I've been using as an example in the rest of
the document. Also, do you have an HTML version of the document?

[1] http://www.w3.org/2001/11/13-RDF-Query-Rules/

> > On Thu, 31 Jan 2002 gt77@gmx.at wrote:
> > 
> > > Hi!
> > >
> > > Im going to write my diploma thesis about evaluating different RDF-query
> > > languages.  Therefore I would like to know, if someone can give me an brief
> > > overview (or interesting links) about the most important and powerful query
> > > languages (like redland or jena), which I should include in my thesis. Many
> > > thanks in advance!
> > >
> > > Gerald
> > >
> > > --
> > > GMX - Die Kommunikationsplattform im Internet.
> > > http://www.gmx.net
> > >
> > >
> > 
> > Hi Gerald. I think other people might have a better summary than I do,
> > but I have a bunch of notes from something else I've been doing about a
> > simple query language that I've been working on with Andy Seaborne
> > called SquishQL, which is why I'm interested (see notes below, which
> > are not comprehensive). You might also like to try
> > www-rdf-rules@w3.org, which is the mailing list
> > for rdf rules and query. Look at its archive:
> > http://lists.w3.org/Archives/Public/www-rdf-rules/
> > 
> > I'm not sure what you mean by 'important and powerful' query langauges.
> > There are a number of RDF management systems out there which include
> > large databases and use query languages. Some don't have query
> > languages, like Redland, but are still very useful and scalable. I've
> > been using a simple RDF query language, because it meets my
> > requirements.
> > 
> > Hope this helps anyway.
> > 
> > Libby
> > 
> > 
> > Some RDF query languages have been in in use for several years.
> > R.V. Guha's rdfDB query language [1] was the first of these (as far as I
> > can tell) and is the basis for SquishQL. It is a simple graph-matching
> > query language designed for use with the rdfDB system. It differs
> > slighty syntactically from SquishQL and also does not contain the
> > constraints on the variables used by SquishQL. It returns results as a
> > table. rdfDB is written in C, I think.
> > 
> > Algae [2] is another early query language for RDF, written by Eric
> > Prud'hommeaux of W3C in Perl. It uses an S-expression syntax to do graph
> > matching. It can handle contraints of some kinds, I think. It is used to
> > power the W3C's Annotea annotations system [3], and other software at
> > the W3C. It's written in Perl, and can be used with an SQL database.
> > 
> > RQL [4] has a very different syntax, based on OQL, but can perform
> > similar sorts of queries, with the added power of syntactic support for
> > transitive closure on RDF subclass and subproperty. It is used by the
> > Sesame system [5].
> > 
> > SquishQL is one of a number of query languages syntactically similar to
> > rdfDB's. These include one by Geoff Chappell for RDFGateway [6], and one
> > by David Allsopp [7]. RDFGateway QL is interesting because it is a
> > simple query language over a database that can understand and process
> > rules. David Allsopp's QL has syntactic support for regex path
> > expressions.
> > 
> > There are a number of other query languages being created at the moment,
> > including a DAML QL [8], Triple [9], RDFPath [10]. There a number of
> > papers at QL98 that you might find helpful, including one by R.V.Guha et
> > al [11] which heavily influenced SquishQL. It might also be worth
> > looking at the notes from the RDF Query birds of a feather meeting last
> > August [12].
> > 
> > I've been working on SquishQL, formerlly Squish[13], a simple SQL-ish
> > RDF query language for a couple of years with Dan Brickley and also with
> > Andy Seaborne of HP, who has done an implementation called RDQL[14] for
> > Jena. I have an implementation called Inkling[15].
> > 
> > [1] http://web1.guha.com/rdfdb/query.html http://guha.com/rdfdb/
> > 
> > [2] http://www.w3.org/2001/Talks/0505-perl-RDF-lib/slide8-0.html
> > 
> > http://ilrt.org/discovery/2001/08/rdfquery-bof/
> > 
> > http://www.w3.org/2001/Annotea/User/Protocol.html
> > 
> > http://www.w3.org/1999/02/26-modules/User/Algae-HOWTO.html (BNF)
> > 
> > http://www10.org/cdrom/papers/488/
> > 
> > [3] http://www.w3.org/2001/Annotea/
> > 
> > [4] A paper on RQL
> >        http://www.ics.forth.gr/proj/isst/RDF/RQL/rql.html
> >        BNF
> >        http://139.91.183.30:9090/RDF/RQL/bnf.html
> >        RQL tutorial
> >        http://sesame.aidministrator.nl/
> > 
> > [5]
> >        http://sesame.aidministrator.nl/
> > 
> > 
> > [6]
> > http://www.intellidimension.com/RDFGateway/Docs/rdfqlgettingstarted.asp
> > 
> > [7] http://ilrt.org/discovery/2001/08/rdfquery-bof/
> >           http://www.semanticweb.org/SWWS/program/full/paper10.pdf
> > 
> > [8] http://www.ai.sri.com/daml/notes/HW2/SemanticWeb/paper.html
> >        http://www.daml.org/listarchive/joint-committee/0572.html
> > 
> > http://lists.w3.org/Archives/Public/www-archive/2001Sep/0016.html
> >        http://www.w3.org/2000/10/swap/test/dpoq22Aug/query-answer.daml
> >        http://www.daml.org/listarchive/joint-committee/0598.html
> > 
> > - probably more by now...
> > 
> > [9]
> > 
> > http://www.daml.org/listarchive/joint-committee/0673.html
> >           http://www.dfki.uni-kl.de/frodo/triple/
> > 
> > [10] http://groups.yahoo.com/group/rdfpath/
> > 
> > 
> > [11] http://www.w3.org/TandS/QL/QL98/pp/enabling.html
> > 
> > [12] http://ilrt.org/discovery/2001/08/rdfquery-bof/
> > 
> > [13] http://ilrt.org/discovery/2000/10/swsql/
> > 
> > [14] http://hpl.hp.com/semweb/
> > 
> > [15] http://swordfish.rdfweb.org/rdfquery/
> > 
> > 
> 
> 
> --
> Wolfgang Nejdl

-- 
-eric

(eric@w3.org)
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Received on Tuesday, 5 February 2002 16:42:11 GMT

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