private void initPredicate() { // determine minimum and maximum values Object min = DataLib.min(m_tuples, m_field).get(m_field); Object max = DataLib.max(m_tuples, m_field).get(m_field); // set up predicate Literal left = Literal.getLiteral(min, m_type); Literal right = Literal.getLiteral(max, m_type); ColumnExpression ce = new ColumnExpression(m_field); RangePredicate rp = new RangePredicate(ce, left, right); setPredicate(rp); }