for (final BasicOperator bo : llbo) {
operatorMustReceiveSortedData(root, bo,
basicOperator.getIntersectionVariables());
}
final BasicOperator newOperator = new MergeWithoutSortingOptional();
newOperator.cloneFrom(basicOperator);
basicOperator.replaceWith(newOperator);
return newOperator;
}
} else if (basicOperator instanceof FastSort) {
if (basicOperator.getPrecedingOperators().size() == 1