Hi Holger, thank you for the information. I finally set up a TDB triplestore with over 53 Mio triples and it shows up perfectly in TBC. But now I'm having performance problems when running SPARQL queries over the triplestore in TBC's SPARQL view. SPIN constraints also seem to run forever. I'm using the 64bit version of TBC 3.3.1 SE and set the java heapspace limit to 6144m.
Is there any configurations the can speed up TBC's queries and SPIN constraints besides query optimization and java heapspace settings? Thanks, Christian On 24 Mai, 03:51, Holger Knublauch <[email protected]> wrote: > Hi Christian, > > TopBraid's Sesame 2 integration is not as optimized as our other database > interfaces. In practice this means that TBC cannot use any native > optimizations that the database server (in your case Virtuoso) may provide. > Instead, it will break down even the most complex SPARQL queries into small > findSPO queries, which may lead to significant performance problems. Maybe > that's why constraint checking apparently did not work for you when you can > SPIN constraints on Virtuoso. With smaller databases this impact may not have > been sufficiently severe to notice. But I am glad that you have been able to > confirm that Virtuoso is working well with TBC in principle. > > Over the week end we also had some enlightening examples of SPARQL queries > that were not optimized: we had a query with three OPTIONAL clauses, leading > to a large number of potential combinations. Replacing those with other > SPARQL patterns were leading to many orders of magnitude speed improvements. > Just saying this in case you have some "dangerous" queries in your > constraints. I assume you have executed the queries individually, e.g. from > the SPARQL view, to test their performance before putting them into your SPIN > constraint library. > > Finally, I discovered a performance issue after running the SPIN constraints > from the Problems View: if hundreds or thousands of violations were found, > then just updating those into the Problems view may freeze the system. I have > just fixed this for 3.3.2 (and 3.4). > > Regards, > Holger > > On May 21, 2010, at 10:25 PM, Christian Fuerber wrote: > > > > > Hi Holger, > > > fortunately i can apply SPIN constraints now on the small graph (245 > > triples) in virtuoso. Although I still do not know what the problem > > was. Maybe. it works now because I reinstalled java. I will also send > > you the error log, in case you are interested. > > > Thanks a lot, > > > Christian > > > On 21 Mai, 00:20, Holger Knublauch <[email protected]> wrote: > >> On May 21, 2010, at 1:08 AM, Christian Fuerber wrote: > > >>> Hi Holger, > > >>> thank you for the quick response. Yes, I could successfully connect to > >>> a graph in virtuoso that has 245 triples. But the SPIN constraint > >>> checks are not working on the graph's data. I receive an error "Could > >>> not run checker" when executing "Refresh and show problems > >>> (constraints)". SPARQL in TBC is also not working. I just can see the > >>> classes and instances in the editor. > > >> Are there any more details available, e.g. the Error Log? > > >> And yes, TDB will almost certainly be faster for SPARQL, because it will > >> "live" in the same JVM, so no communication overhead is needed. > >> Furthermore, TDB is better optimized to work with the ARQ SPARQL engine. > > >> Thanks > >> Holger > > >> -- > >> You received this message because you are subscribed to the Google > >> Group "TopBraid Suite Users", the topics of which include TopBraid > >> Composer, > >> TopBraid Live, TopBraid Ensemble, SPARQLMotion and SPIN. > >> To post to this group, send email to > >> [email protected] > >> To unsubscribe from this group, send email to > >> [email protected] > >> For more options, visit this group > >> athttp://groups.google.com/group/topbraid-users?hl=en > > > -- > > You received this message because you are subscribed to the Google > > Group "TopBraid Suite Users", the topics of which include TopBraid Composer, > > TopBraid Live, TopBraid Ensemble, SPARQLMotion and SPIN. > > To post to this group, send email to > > [email protected] > > To unsubscribe from this group, send email to > > [email protected] > > For more options, visit this group at > >http://groups.google.com/group/topbraid-users?hl=en > > -- > You received this message because you are subscribed to the Google > Group "TopBraid Suite Users", the topics of which include TopBraid Composer, > TopBraid Live, TopBraid Ensemble, SPARQLMotion and SPIN. > To post to this group, send email to > [email protected] > To unsubscribe from this group, send email to > [email protected] > For more options, visit this group > athttp://groups.google.com/group/topbraid-users?hl=en -- You received this message because you are subscribed to the Google Group "TopBraid Suite Users", the topics of which include TopBraid Composer, TopBraid Live, TopBraid Ensemble, SPARQLMotion and SPIN. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/topbraid-users?hl=en
