code: public int size() throws SQLException {
      int cp = tell();
      seek(0, SEEK_END);
      int sz = tell();
      seek(cp, SEEK_SET);
      return sz;
    }
docs: <p>This method is inefficient, as the only way to find out the size of the object is to seek to
  the end, record the current position, then return to the original position.</p>
  
  <p>A better method will be found in the future.</p>
  
  @return the size of the large object
  @throws SQLException if a database-access error occurs.