Thomas, Quads are stored in RDF_QUAD table, as follows:
create table DB.DBA.RDF_QUAD ( G IRI_ID, S IRI_ID, P IRI_ID, O any, primary key (G,S,P,O) ) create bitmap index RDF_QUAD_OGPS on DB.DBA.RDF_QUAD (O, G, P, S) ; (the very beginning of libsrc/Wi/sparql.sql if you build from sources.) If you performs queries that does not specify fixed graph names, but specify fixed predicates, the following indexes are quite useful: create bitmap index RDF_QUAD_PSOG on DB.DBA.RDF_QUAD (P, S, O, G); create bitmap index RDF_QUAD_POSG on DB.DBA.RDF_QUAD (P, O, S, G); You can create other indexes as well. Bitmap indexes are preferable, but if O is the last column then the index can not be bitmap, so it could be, e.g. create index RDF_QUAD_PSGO on DB.DBA.RDF_QUAD (P, S, G, O); but not create bitmap index RDF_QUAD_PSGO on DB.DBA.RDF_QUAD (P, S, G, O); Best Regards, Ivan Mikhailov, OpenLink Software. On Fri, 2008-02-22 at 15:46 +0100, Thomas Hornung wrote: > Hi, > > are there any special indices that can be turned on for querying RDF > data, e.g. subject/object -> predicate? AFAI understand the > documentation there is the possibility to use full text indices for > literals in the object position ( as mentioned in > http://docs.openlinksw.com/virtuoso/rdfsparqlrulefulltext.html), but I > couldn't find information on where to tweak other indices. > > Does somebody know, if "special" indices are supported or are all > indices generated as a default setting. > > Best regards, > Thomas >
