DatabaseEntry data = new DatabaseEntry();
data.setPartial(0, 0, true);// do not retrieve data
List<ObjectId> matches;
CursorConfig cursorConfig = new CursorConfig();
cursorConfig.setReadUncommitted(true);
Transaction transaction = null;
Cursor cursor = objectDb.openCursor(transaction, cursorConfig);
try {
// position cursor at the first closest key to the one looked up