Thanks for your response.
We are developing a system that includes prediction models in the cheminformatics domain. So there is a lot of (cheminformatics) data that is stored in our database and fits very well into it. We are not sure about the numeric data below, though. But we want to have it all in a single database (and avoid storing sth on the file system or in an additional sql database, if possible).

Kind regards,
Martin

Am 07.06.2016 um 21:54 schrieb A. Soroka:
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)
Email:
[email protected]



--
Dr. Martin Gütlein
Phone:
+49 (0)6131 39 23336 (office)
Email:
[email protected]

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