Write out Oracle models to RDF

Question

I am trying to write models I have in my Oracle 12c database to RDF. I am using Jena, and the code goes something like this:
Oracle oracle = f.getOracle(); //My shortcut to getting access to the database, and give me an Oracle object.
Model model;
try {  model = ModelOracleSem.createOracleSemModel(oracle, modelName); }
catch (SQLException ex) {
//errorhandling
model.write(out);
Now, this works. But it works so terribly slow. I can almost see each individual triple downloaded. 30mb takes me three hours, which is totally unusable.
Are there other ways of doing this?

Answer 1

Here is a quick test I did.
I have a graph with 60.9M triples. And on my machine (a quad core CPU and Samsung 840 SSD), I can dump it out in a few minutes.
$ time java -Doracle.net.disableOob=true -cp ./classes:./'*' TestWrite jdbc:oracle:thin:@127.0.0.1:1521:db12c scott tiger mygraph 4
117.632u 6.941s 7:50.38 26.4%   0+0k 4360+11611520io 33pf+0w
The output is almost 6GB in size.
5,944,877,703 Nov 18 16:42 dump.nt
------- Source code is as follows ----
$ cat TestWrite.java
import java.io.*;
import com.hp.hpl.jena.query.*;
import com.hp.hpl.jena.rdf.model.Model;
import com.hp.hpl.jena.util.FileManager;
import oracle.spatial.rdf.client.jena.*;
public class TestWrite {
  public static void main(String[] args) throws Exception
    String szJdbcURL = args[0];
    String szUser    = args[1];
    String szPasswd  = args[2];
    String szModelName = args[3];
    Oracle oracle = new Oracle(szJdbcURL, szUser, szPasswd);
    ModelOracleSem model = ModelOracleSem.createOracleSemModel(oracle, szModelName);
    GraphOracleSem gos = model.getGraph();
    gos.setDOP(Integer.parseInt(args[4]));
    OutputStream os = new FileOutputStream("/tmp/dump.nt");
    model.write(os, "N-TRIPLE");
    os.close();