db.open(databaseName, Database.OPEN_READ_WRITE);
Transaction tx = odmg.newTransaction();
tx.begin();
for (int i = 0; i < arr.length; i++)
{
db.deletePersistent(arr[i]);
}
tx.commit();
db.close();
long stop = System.currentTimeMillis();
times[3] = times[3] + (stop - start);