// performed
// 1 - discount
final ValueExpression<Double> substract = new Subtraction(new ValueSpecification(
_doubleConv, 1.0), new ColumnReference(_doubleConv, 1));
// extendedPrice*(1-discount)
final ValueExpression<Double> product = new Multiplication(new ColumnReference(_doubleConv,
0), substract);
final AggregateOperator agg = new AggregateSumOperator(product, conf);
// /Join predicate
final ColumnReference colLineItems = new ColumnReference(_ic, 0);
final ColumnReference colOrders = new ColumnReference(_ic, 0);
final ComparisonPredicate pred1 = new ComparisonPredicate(ComparisonPredicate.EQUAL_OP,
colLineItems, colOrders);
final ValueSpecification value10 = new ValueSpecification(_doubleConv, 10.0);
final ColumnReference colLineItemsInequality = new ColumnReference(_doubleConv, 1);
final Multiplication mult = new Multiplication(value10, colLineItemsInequality);
final ColumnReference colOrdersInequality = new ColumnReference(_doubleConv, 1);
final ComparisonPredicate pred2 = new ComparisonPredicate(ComparisonPredicate.LESS_OP,
mult, colOrdersInequality);
final AndPredicate overallPred = new AndPredicate(pred1, pred2);