- From: Bijan Parsia <bparsia@cs.manchester.ac.uk>
- Date: Sat, 9 May 2009 18:12:23 +0100
- To: Sandro Hawke <sandro@w3.org>
- Cc: RIF WG <public-rif-wg@w3.org>
On 9 May 2009, at 13:40, Sandro Hawke wrote: [snip] > Right. The interesting/challening part, I believe, is that Gary wants > to translate frames to Java objects. Doing so will require some > cleverness, since there are significant semantics/functionality > differences, but hopefully will give significant performance gains. > Ternary predicates are typically not super fast at matching (a,b,?). Really? > (For example, SWI-Prolog uses a specially indexed structure for RDF > triples/quads, because normal predicate indexing is too slow.) I wouldn't think that's the issue. Predicate indexing is typically one of the more optimized part of a Prolog engine (for obvious reasons). A uniform ternary predicate *defeats* predicate indexing because there's only one predicate. By default, IIRC and it hasn't changed, most Prolog engines do predicate plus first argument indexing, though you can change that, e.g.,: http://www.lix.polytechnique.fr/~catuscia/teaching/prolog/Manual/sec-3.11.html#sec :3.11.1 http://www.lix.polytechnique.fr/~catuscia/teaching/prolog/Manual/sec-3.12.html#index/ 1 Cheers, Bijan.
Received on Saturday, 9 May 2009 17:13:04 UTC