Import of RDF-Triple - HOW?

Question

Hello,
i have some problem:
I have just installed Oracle 11g. Now, i want to upgrade the database so that I can import RDF-Triple of the type "N3" into my Database. My questions now are:
1. What do I have to do, to be able to import these triples? Is there any tutorial, that explaines, how I can upgrade for RDF-Import?
2. When I successfully upgraded my database, how can I import my triples? Can I import N3-TRIPLES or do I have to convert them?
It would be nice, if anyone can help me.
Chris

Answer 1

Hello guys,
I am trying to Import some N3-Triple to my Database.
I opened SQL*PLUS and logged in with user: 'SYSTEM'
First, I installed the RDF-stuff with SQL'PLUS by typing @catsem11i.sql;
Then, i did the following steps:
1) CREATE TABLESPACE rdf_tablespace
DATAFILE '/local/oracle/app/oracle/oradata/THESEUSDl/rdf_tablespace.dat' SIZE 1024M REUSE
AUTOEXTEND ON NEXT 256M MAXSIZE UNLIMITED
SEGMENT SPACE MANAGEMENT AUTO;
2) EXECUTE SDO_RDF.CREATE_RDF_NETWORK('rdf_tablespace');
3) GRANT EXECUTE ON MDSYS.RDF_APIS_INTERNAL TO SYS;
4) CREATE TABLE RDF_DATA (id NUMBER, triple SDO_RDF_TRIPLE_S);
5) EXECUTE SDO_RDF.CREATE_RDF_MODEL('RDF', 'RDF_DATA', 'TRIPLE');
Well, then I took my littel Java-file for importing the triples:
here is my code:
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintStream;
import java.sql.SQLException;
import oracle.spatial.rdf.client.jena.GraphOracleSem;
import oracle.spatial.rdf.client.jena.ModelOracleSem;
import oracle.spatial.rdf.client.jena.Oracle;
import oracle.spatial.rdf.client.jena.OracleBulkUpdateHandler;
import com.hp.hpl.jena.graph.GraphUtil;
import com.hp.hpl.jena.rdf.model.Model;
import com.hp.hpl.jena.rdf.model.ModelFactory;
import com.hp.hpl.jena.util.FileManager;
public class Import {
     * @param args
     * @throws ClassNotFoundException
     * @throws SQLException
     * @throws IOException
     public static void main(String[] args) throws ClassNotFoundException,
               SQLException, IOException {
          PrintStream psOut = System.out;
          String tbs = "rdf_tablespace";
          int method = 1;
          String className = "oracle.jdbc.driver.OracleDriver"; // path of driver
          // class
          Class.forName(className); // Load the Driver
          String DB_URL = "jdbc:oracle:thin:@URL:1521:THESEUSDB"; // URL of database
          String DB_USER = "SYSTEM"; // database user id
          String DB_PASSWD = "secret_pw"; // database password
          String DB = "Oracle"; // database type
          // Create database connection
          Oracle oracle = new Oracle(DB_URL, DB_USER, DB_PASSWD);
          // darf nicht mit einer zahl anfangen
          String modelName = "onehoundred";
          // create or open the default model
          Model model = ModelFactory.createDefaultModel();
          GraphOracleSem graph = new GraphOracleSem(oracle, modelName);
          // read data
          String filename = "C:\\Path\\sp2b_100000.n3";
          InputStream is = FileManager.get().open(filename);
          // for n3 files
          model.read(is, "", "N3");
          is.close();
          ModelOracleSem modelDest = ModelOracleSem.createOracleSemModel(oracle,
                    modelName);
          GraphOracleSem g = modelDest.getGraph();
          g.dropApplicationTableIndex();
          //batch
               psOut.println("start batch load");
               ((OracleBulkUpdateHandler) g.getBulkUpdateHandler()).addInBatch(
                         GraphUtil.findAll(model.getGraph()), tbs);
               psOut.println("end size " + modelDest.size());
          g.rebuildApplicationTableIndex();
          modelDest.close();
          // Close the database connection
          oracle.dispose();
          System.out.println("Ready.");
I run it - it takes about 3 minutes - and the i get the following result:
start batch load
end size 100073
Ready.
So far, so good. But now, i have a little problem. If i look into my Database (with DBVisualizer) , i cannot find my imported triples...
I don't understand why. In my Java Code, I have "String tbs = "rdf_tablespace"" which I also created before with SQL*Plus. And in that tablespace should be my table "RDF_DATA", i guess. So do I understand anything wrong? Did I forget any step?
Who can help? I am very desperate right now :-)