On Tue, Apr 2, 2013 at 10:45 PM, Hasan Hasan <[email protected]> wrote:
> Hi Reto, > > after studying carefully the description and examples in > http://www.w3.org/TR/sparql11-query/#rdfDataset > I think the PreParser should - as you suggested - have a TcProvider to > return all TripleCollections, in case no FROM NAMED clause is specified in > the query. > > How should we pass the TcProvider to the PreParser? In a separate method, > e.g., > > public void setTcProvider(TcProvider tcProvider); > I think we could have a constructor that takes a TcProvider while the service would always use TcManager. Cheers, Reto > > Default TcProvider would be TcManager. > > Cheers > Hasan > > > > On Tue, Apr 2, 2013 at 12:34 PM, Reto Bachmann-Gmür <[email protected]> > wrote: > > > Hi, > > > > The query SELECT DISTINCT ?g { GRAPH ?g { ?s ?p ?o } } can obviously only > > be answered correctly by a sparql engine that knows about all the > available > > graphs. As typically not all graphs are provided by the same provider > this > > means the query has to be slow laned. > > > > If the pre parser returns only the default graph as this is currently the > > case: > > > > zz>spp.getReferredGraphs("SELECT DISTINCT ?g { GRAPH ?g { ?s ?p ?o } > }",new > > UriRef("urn:x-localinstance:/content.graph")) > > res0: java.util.Set[org.apache.clerezza.rdf.core.UriRef] = > > [<urn:x-localinstance:/content.graph>] > > > > The query would be fastlaned to the TcProvider providing the Graph > > <urn:x-localinstance:/content.graph> which potentially knows about none > of > > the other graphs. > > > > So I think either the preparser has the TcManager and returns all the > > TripleCollections or it returns a special value to tell the caller that > the > > set of affected graphs cannot be limited (return null). > > > > Currently clerezza correctly returns all triple collections: > > > > zz>val q = qp.parse("SELECT DISTINCT ?g { GRAPH ?g { ?s ?p ?o } }") > > q: org.apache.clerezza.rdf.core.sparql.query.Query = > > SELECT DISTINCT > > ?g > > WHERE > > { GRAPH ?g { ?s ?p ?o . > > } } > > zz>val r = tcm.executeSparqlQuery(q.asInstanceOf[SelectQuery], new > > SimpleMGraph) > > r: org.apache.clerezza.rdf.core.sparql.ResultSet = > > org.apache.clerezza.rdf.jena.sparql.ResultSetWrapper@b0d2ffd > > zz>r.next > > res5: org.apache.clerezza.rdf.core.sparql.SolutionMapping = > > {org.apache.clerezza.rdf.core.sparql.query.Variable@67 > > =<urn:x-localinstance:/tbox.graph>} > > zz>r.next > > res6: org.apache.clerezza.rdf.core.sparql.SolutionMapping = > > {org.apache.clerezza.rdf.core.sparql.query.Variable@67 > > =<urn:x-localinstance:/config.graph>} > > zz>r.next > > res7: org.apache.clerezza.rdf.core.sparql.SolutionMapping = > > {org.apache.clerezza.rdf.core.sparql.query.Variable@67 > > =<urn:x-localinstance:/content.graph>} > > zz>r.next > > res8: org.apache.clerezza.rdf.core.sparql.SolutionMapping = > > {org.apache.clerezza.rdf.core.sparql.query.Variable@67 > > =<urn:x-localinstance:/documentation.graph>} > > zz>r.next > > res9: org.apache.clerezza.rdf.core.sparql.SolutionMapping = > > {org.apache.clerezza.rdf.core.sparql.query.Variable@67 > > =<urn:x-localinstance:/web-resources-cache.graph1364897492157>} > > zz>r.next > > res10: org.apache.clerezza.rdf.core.sparql.SolutionMapping = > > {org.apache.clerezza.rdf.core.sparql.query.Variable@67 > > =<urn:x-localinstance:/graph-access.graph>} > > zz>r.next > > res11: org.apache.clerezza.rdf.core.sparql.SolutionMapping = > > {org.apache.clerezza.rdf.core.sparql.query.Variable@67 > > =<urn:x-localinstance:/web-resources.graph>} > > zz>r.next > > res12: org.apache.clerezza.rdf.core.sparql.SolutionMapping = > > {org.apache.clerezza.rdf.core.sparql.query.Variable@67 > > =<urn:x-localinstance:/system.grap > > > > Cheers, > > Reto > > > > On Tue, Apr 2, 2013 at 8:10 AM, Hasan Hasan <[email protected]> wrote: > > > > > Hi Reto, all > > > > > > Two issues here: > > > > > > First the query: SELECT DISTINCT ?g { GRAPH ?g { ?s ?p ?o } } > > > does not specify NAMED graphs. > > > If the query is as follows > > > SELECT DISTINCT ?g FROM NAMED http://example.org/g1 { GRAPH ?g { ?s ?p > > ?o > > > } > > > } > > > then the engine will return http://example.org/g1 > > > because the clause GRAPH refers only NAMED graphs as mentioned by Andy > > > > > > Second the parser: I think the parser needs not know about TcManager or > > > other providers in this case, because > > > the named graphs are all specified in the query. > > > > > > Cheers > > > Hasan > > > > > > > > > > > > On Fri, Mar 29, 2013 at 1:47 PM, Reto Bachmann-Gmür (JIRA) > > > <[email protected]>wrote: > > > > > > > > > > > [ > > > > > > > > > > https://issues.apache.org/jira/browse/CLEREZZA-761?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13617295#comment-13617295 > > > ] > > > > > > > > Reto Bachmann-Gmür commented on CLEREZZA-761: > > > > --------------------------------------------- > > > > > > > > zz>import org.apache.clerezza.rdf.core.sparql._ > > > > import org.apache.clerezza.rdf.core.sparql._ > > > > zz>val spp = $[SparqlPreParser] > > > > spp: org.apache.clerezza.rdf.core.sparql.SparqlPreParser = > > > > org.apache.clerezza.rdf.core.sparql.SparqlPreParser@3aa78e7a > > > > zz>spp.getReferredGraphs("SELECT DISTINCT ?g { GRAPH ?g { ?s ?p ?o } > > }", > > > > new UriRef("urn:x-localinstance:/content.graph")) > > > > res0: java.util.Set[org.apache.clerezza.rdf.core.UriRef] = > > > > [<urn:x-localinstance:/content.graph>] > > > > zz> > > > > > > > > As discussed in > > > > > > > > > > http://mail-archives.apache.org/mod_mbox/clerezza-dev/201303.mbox/%[email protected]%3Ethisshouldreturnall > the graphs in the dataset. I think that > > > > SParqlPreParser being a service it could consider by default > TcManager > > > > being the dataset, but it probably should also have a method that > takes > > > any > > > > TcProvider as dataset and return it's triple collections. > > > > > > > > > Implement SPARQL PreParser to support fastlane > > > > > ---------------------------------------------- > > > > > > > > > > Key: CLEREZZA-761 > > > > > URL: > > > https://issues.apache.org/jira/browse/CLEREZZA-761 > > > > > Project: Clerezza > > > > > Issue Type: New Feature > > > > > Reporter: Hasan > > > > > Assignee: Hasan > > > > > > > > > > The purpose is to have a class with a method to obtain referred > > graphs > > > > in a SPARQL Query or SPARQL Update > > > > > > > > -- > > > > This message is automatically generated by JIRA. > > > > If you think it was sent incorrectly, please contact your JIRA > > > > administrators > > > > For more information on JIRA, see: > > > http://www.atlassian.com/software/jira > > > > > > > > > >
