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Re: SWI-Prolog 3.3.7

From: Jan Wielemaker <jan@swi.psy.uva.nl>
Date: Tue, 13 Jun 2000 15:01:30 +0200
To: Dan Brickley <danbri@w3.org>
Cc: www-rdf-interest@w3.org
Message-Id: <00061315470704.24662@gollem>
On Fri, 09 Jun 2000, you wrote:
>Hi Jan,
>
>The on-disk stuff sounds fun. Have you a sketch of what the BerkelyDB
>representation will look like? I know RDF types have been playing with
>this idea, and if a common way of using BerkeleyDB could be adopted this'd
>let Perl scripts etc access that same data...

Dan,

I've been thinking a bit on that.  Basically, Berkeley DB associates
'binary-blobs'.  What you do inside them is up to you.  There are two
routes to deal with RDF, Prolog and DB.

One is to define a format for RDF directly in these binary blobs and
then add an interface to Prolog, Perl, Java, ... to deal with this
data.

The other is to define a layer that makes DB a natural extension to
Prolog, and then define the RDF stuff on top of that.  This is probably
a little less efficient (as the implementation has to deal with things
not needed for RDF), but it makes the connection in the light of Prolog
suitable for many other tasks.

I've decided for the second route.  This makes direct access to the RDF
DB from Perl, Java, etc. infeasible.  Using Prolog as an intermediate
will be the only way to talk to the RDF DB.

Of course, if someone comes up with a good RDF representation in DB
we can always look for a Prolog connection.  Problem is that there is
probably not `one good representation for RDF in DB': it depends on
the expressiveness of the query language, the queries you want to
be efficient and the time/space tradeof.

	Regards --- Jan
Received on Tuesday, 13 June 2000 09:47:11 GMT

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