Re: Scope

Hello,

I will quickly outline what I have been doing in the last months. RDFStore [1] is  a
perl extension that includes an RDF API, a parser and a hashed data database storage
which support RDQL [2]. The package does include a generic data storage system that
allows to serialise RDF an abstract syntax/model,  resources, properties and property
values either to disk or in-memory data structures. It does support several different
persistent storage models such as SDBM, BerkeleyDB (standard and Sleepycat) and DBMS.
The latter is a custom TCP/IP based storage library that allows to a perl script to
transparently read/write hashed data values sitting on a remote database server
similar to rdfdb [3].
The RDQL support in RDFStore includes a simple top-down parser implementing the
grammar proposed by Andy (and others); by leveraging on the internal indexing method I
added  a LIKE  operator to grep large result sets such as

(?item, <rss:title>, %"freetext"%)

or in the constraints clause as

(?item, <rss:title>, ?title) AND ?title LIKE '/freetext/i'

The basic plan is to bundle RDFStore as perl DBI driver to run such queries over local
or remote storage, and use a standardized query language and API over it. I am also
investigating the possibility to embed such RDF "operations" directly into the perl
language, but this is more for the far future.

I am not a logician and apologize me if the terminology used in this email is wrong.

regards

Alberto

[1] http://rdfstore.sourceforge.net/
[2] http://rdfstoredemo.jrc.it/rdql/
[3] http://groups.yahoo.com/group/rdfstore/message/14

Dan Brickley wrote:

> Hi all
>
> This list (as yet not widely announced / publicised, in part due to the
> difficulty of nailing down a scope) is indeed for both RDF 'rules' and
> RDF 'query' discussions.  The distinction is perhaps more easily made in
> terms of differing communities and expectations than in terms of these
> being crisply distinguishable technologies. We will have a mix of
> backgrounds and terminology here, which is something to be aware of as you
> read posts from others. EricP suggested some ideas common terminology,
> which was a useful way of opening up initial discussion.
>
> One way to get started on some detail might be for people to focus on what
> they've built, prototyped etc to date in this area using RDF. Setting
> aside for now the question of 'what is RDF _query_ versus _rules_', and
> swapping some brief summaries of what tools, techniques we've used for doing things
> like asking questions of an RDF database/service or representing
> and using inference rules over RDF content. We can worry about whether to
> call it a database or a knowledgebase, a query language or a logic system
> etc etc later. First, I'd love to know what people have been building...
>
> Anybody want to get us started?
>
> danbri
>
> --
> mailto:danbri@w3.org
> http://www.w3.org/People/DanBri/

Received on Tuesday, 13 November 2001 03:55:16 UTC