code: public synchronized long length() throws SQLException {
  
          try {
              return blob.length(session);
          } catch (HsqlException e) {
              throw Util.sqlException(e);
          }
      }
docs: Returns the number of bytes in the <code>BLOB</code> value designated
  by this <code>Blob</code> object.
  
  @return length of the <code>BLOB</code> in bytes
  @throws SQLException if there is an error accessing the length of the
  <code>BLOB</code>