final ColumnReference suppKey = new ColumnReference(_sc, 2);
// forth field in projection
final ValueExpression<Double> substract = new Subtraction(new ValueSpecification(
_doubleConv, 1.0), new ColumnReference(_doubleConv, 6));
// extendedPrice*(1-discount)
final ValueExpression<Double> product = new Multiplication(new ColumnReference(_doubleConv,
5), substract);
final ProjectOperator projectionLineitem = new ProjectOperator(orderKey, partKey, suppKey,
product);
final DataSourceComponent relationLineitem = new DataSourceComponent("LINEITEM", dataPath