This seems like a bit of an odd usage for an RDF store. Could you explain a bit more why you want to put this data into Jena? Are you already using Jena for other data in your work?
--- A. Soroka The University of Virginia Library > On Jun 7, 2016, at 11:22 AM, Martin Gütlein <[email protected]> wrote: > > Hi, > > we would like to store some tables with double values in our triple store. At > the moment we are doing this by creating row and entry resources (see code > below). > However, it is rather time and space consuming for medium sized tables. E.g. > a 500x500 table takes 20seconds and the the db size is 156MB. For our project > we plan to save larger/more data (and add some more semantic info). > > Is there a more efficient way to do that? > > Kind regards, > Martin > > Here is our example code: > > int cols = 500; > int rows = 500; > > double myTable[][] = new double[rows][cols]; > for (int r = 0; r < rows; r++) > for (int c = 0; c < cols; c++) > myTable[r][c] = new Random().nextDouble(); > > String directory = "myDB/tdb"; > Dataset dataset = TDBFactory.createDataset(directory); > > Model model = dataset.getDefaultModel(); > String NS = "http://my-namespace/test/";; > > Property hasRow = model.createProperty(NS + "hasRow"); > Property rowIndex = model.createProperty(NS + "rowIndex"); > Property hasEntry = model.createProperty(NS + "hasEntry"); > Property colIndex = model.createProperty(NS + "colIndex"); > Property value = model.createProperty(NS + "value"); > > Resource table = model.createResource(NS + "table/" + > UUID.randomUUID()); > > for (int r = 0; r < rows; r++) > { > Resource row = model.createResource(NS + "row/" + > UUID.randomUUID()); > table.addProperty(hasRow, row); > row.addProperty(rowIndex, r + "", XSDDatatype.XSDint); > > for (int c = 0; c < cols; c++) > { > Resource entry = model.createResource(NS + "entry/" + > UUID.randomUUID()); > row.addProperty(hasEntry, entry); > entry.addProperty(colIndex, c + "", XSDDatatype.XSDint); > entry.addProperty(value, myTable[r][c] + "", > XSDDatatype.XSDdouble); > } > } > > dataset.end(); > dataset.close(); > > > -- > Dr. Martin Gütlein > Phone: > +49 (0)6131 39 23336 (office) > +49 (0)177 623 9499 (mobile) > Email: > [email protected] >
