- From: pat hayes <phayes@ai.uwf.edu>
- Date: Fri, 28 Jun 2002 00:36:38 -0500
- To: Dan Connolly <connolly@w3.org>
- Cc: w3c-rdfcore-wg@w3.org
>On Thu, 2002-06-27 at 01:40, Patrick Stickler wrote: >> >> >> On 2002-06-26 20:38, "ext Brian McBride" <bwm@hplb.hpl.hp.com> wrote: >> >> >> In the introduction, it would be good, I think, to add a comment >> that the tidy/untidy issue has little to do with implementational >> efficiency of triples stores, > >not true; see comments from Sergey a long time ago about >the cost of untidy literals in RDF/database systems. > >Sorry I don't have time to find it. I recall. But Sergey was being alarmist about a worst-possible case where every triple contained a literal and every literal might or might not be the same as any other. That will never happen. > >The swap/cwm implementation would suffer a significant >efficiency hit if literals weren't tidy. Im not convinced of this. Sure, the code would get a bit more complicated, but I bet that any efficiency cost could be kept marginal, way below a linear factor in practice. If the graphs are encoded in the extended Ntriples convention then there should be no extra cost at all: literal nodes act just like bnodes, uniquely specified by their nodeIDs. If they are encoded in RDF/XML then the only cases which arise will be those that we introduce deliberately to handle some XML idioms, which can be recognized during round-tripping one triple at a time by looking at the property urirefs. That is just a few extra operations per triple, at worst. Pat > > http://www.w3.org/2000/10/swap/ > >esp in def loadToStore(store, addr): > > store.storeQuad((store._experience, > store.semantics, > store.intern((SYMBOL, addr)), > store.intern((FORMULA, addr + "#_formula" )))) > > -- http://www.w3.org/2000/10/swap/llyn.py > >> but is a conceptual distinction >> relating to the graph semantics and that there are numerous ways >> for actual implementations to compress untidyness in the conceptual >> graph in an actual triples store, etc. > >-- >Dan Connolly, W3C http://www.w3.org/People/Connolly/ -- --------------------------------------------------------------------- IHMC (850)434 8903 home 40 South Alcaniz St. (850)202 4416 office Pensacola, FL 32501 (850)202 4440 fax phayes@ai.uwf.edu http://www.coginst.uwf.edu/~phayes
Received on Friday, 28 June 2002 01:36:38 UTC