// 5) Create a candidate for the Iteration Node for every remaining plan of the step function.
final GlobalProperties gp = new GlobalProperties();
gp.setHashPartitioned(this.solutionSetKeyFields);
gp.addUniqueFieldCombination(this.solutionSetKeyFields);
LocalProperties lp = LocalProperties.EMPTY.addUniqueFields(this.solutionSetKeyFields);
// take all combinations of solution set delta and workset plans
for (PlanNode solutionSetCandidate : solutionSetDeltaCandidates) {