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]
