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Rob On 29/10/2013 10:05, "Samir Hamitouche" <[email protected]> wrote: > >Hello, > >please i want UnSubscription, can you help me to remove my email from >this list of users of jena please i have any more memory space to receive >messages > > >thank you very much > >Best regards > >Samir > > > >----- Mail original ----- >De: "Andy Seaborne" <[email protected]> >À: [email protected] >Envoyé: Mardi 29 Octobre 2013 10:34:16 >Objet: Re: Writing big models to disk > >On 29/10/13 08:02, Nikolaos Konstantinou wrote: >> Dear all, >> I am trying to write an RDF file to disk, using the following code: > >Which version of Jena is this? > >> resultModel.write(new BufferedWriter(new FileWriter("file.rdf")), "N3"); > >Aside: Better top flush the BufferedWriter explicitly: > >BufferedWriter x = new BufferedWriter(....) >resultModel.write(x, "N3") ; >x.flush() ; > >or close it explicitly. > >> All works ok when the file is less than 100mb. >> When the file is larger, this has a strange behaviour: the program does >>not throw an exception, java runtime does not throw an out-of-memory >>error, and yet the file does not get written. I have increased java >>memory to -Xmx3072m >> The same model can be successfully stored using SDB (>1.5 million >>triples), so I guess the problem is not in the model. I guess it is a >>general Java issue? >>(http://www.java-forums.org/new-java/42031-writing-huge-sized-file-data-m >>ore-than-100mb-output-stream-converting-byte.html) >> Did anyone else have this issue? Has anyone succeeded in writing rdf >>files larger than 100mb to disk (and how)? > >Are you sure it is no just being very, very slow? > >http://jena.apache.org/documentation/io/rdf-output.html > >"N3" (better, "TTL") is trying to pretty print the data which requires >analysing the data first. That can involve of small probes in the data >which for a database is terrible for performance especially if done >outside a transaction. > >You need to use a format that does less analysis e.g. >RDFFormat.TURTLE_BLOCKS with RDFDataMgr. > > >> Thank you in advance for your support. >> Best regards,Nikolaos Konstantinou >> >> > >Is resultModel stored in SDB? > >Try the following: > >OutputStream out = new FileOutputStream >RDFDataMgr.write(out, resultModel, RDFFormat.NTRIPLES) ; >// Or lang.NTRIPLES > >which is the best scaling output. RDFFormat.TURTLE_BLOCKS isn't bad >though. > > Andy >
