// 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);
}