Since we didn't just query triples, but more than that.. So we put everything into database and try to rewrite the SPARQL. (simply rewriting is easy, but for some complex SPARQL query is hard.) I notice there should be such things in SDB and it would be nice to see it and extend it..
-- Cong Wang Sent with Sparrow (http://www.sparrowmailapp.com/?sig) On Friday, August 3, 2012 at 11:41 AM, Andy Seaborne wrote: > On 02/08/12 12:45, Damian Steer wrote: > > -----BEGIN PGP SIGNED MESSAGE----- > > Hash: SHA1 > > > > On 02/08/12 11:27, Cong Wang wrote: > > > Hi Andy, > > > > > > I am trying to extend some code of sparql to sql in SDB.. > > > > > > Can you give some points where they are in SDB source code ? > > > > Try > > > > src/com/hp/hpl/jena/sdb/compiler/SDBCompile.java > > > > That kicks everything off, and sets the basic features of the databases. > > > > After that maybe QueryCompilerMain.java and TransformSDB.java? The > > basic idea is to taking an input Op -- the query in SPARQL algebra > > form -- and run through it replacing it with OpSQLs which contain a > > representation of the equivalent SQL (SqlNode) where possible. > > > > Damian > > What aspect of the SPARQL->SQL conversion are you looking at? There is > quite a tight binding to the SPARQL execution in ARQ as well. > > Andy > > >
