code: public synchronized String getSubString(long pos,
              int length) throws SQLException {
  
          if (!isInLimits(Long.MAX_VALUE, pos - 1, length)) {
              throw Util.outOfRangeArgument();
          }
  
          try {
              return clob.getSubString(session, pos - 1, length);
          } catch (HsqlException e) {
              throw Util.sqlException(e);
          }
      }
docs: Retrieves a copy of the specified substring in the <code>CLOB</code>
  value designated by this <code>Clob</code> object.
  
  @param pos the first character of the substring to be extracted. The
  first character is at position 1.
  @param length the number of consecutive characters to be copied
  @return a <code>String</code> that is the specified substring in the
  <code>CLOB</code> value designated by this <code>Clob</code> object
  @throws SQLException if there is an error accessing the
  <code>CLOB</code> value