org.apache.flink.optimizer.dataproperties.InterestingProperties Java Examples

@Override
public void computeInterestingPropertiesForInputs(CostEstimator estimator) {
	final InterestingProperties iProps = new InterestingProperties();

	{
		final RequestedGlobalProperties partitioningProps = new RequestedGlobalProperties();
		iProps.addGlobalProperties(partitioningProps);
	}

	{
		final Ordering localOrder = getOperator().getLocalOrder();
		final RequestedLocalProperties orderProps = new RequestedLocalProperties();
		if (localOrder != null) {
			orderProps.setOrdering(localOrder);
		}
		iProps.addLocalProperties(orderProps);
	}
	
	this.input.setInterestingProperties(iProps);
}
 

@Override
public void computeInterestingPropertiesForInputs(CostEstimator estimator) {
	final InterestingProperties iProps = new InterestingProperties();

	{
		final RequestedGlobalProperties partitioningProps = new RequestedGlobalProperties();
		iProps.addGlobalProperties(partitioningProps);
	}

	{
		final Ordering localOrder = getOperator().getLocalOrder();
		final RequestedLocalProperties orderProps = new RequestedLocalProperties();
		if (localOrder != null) {
			orderProps.setOrdering(localOrder);
		}
		iProps.addLocalProperties(orderProps);
	}
	
	this.input.setInterestingProperties(iProps);
}
 

@Override
public void computeInterestingPropertiesForInputs(CostEstimator estimator) {
	final InterestingProperties iProps = new InterestingProperties();

	{
		final RequestedGlobalProperties partitioningProps = new RequestedGlobalProperties();
		iProps.addGlobalProperties(partitioningProps);
	}

	{
		final Ordering localOrder = getOperator().getLocalOrder();
		final RequestedLocalProperties orderProps = new RequestedLocalProperties();
		if (localOrder != null) {
			orderProps.setOrdering(localOrder);
		}
		iProps.addLocalProperties(orderProps);
	}
	
	this.input.setInterestingProperties(iProps);
}
 

@Override
public void computeInterestingPropertiesForInputs(CostEstimator estimator) {
	// get what we inherit and what is preserved by our user code 
	final InterestingProperties props = getInterestingProperties().filterByCodeAnnotations(this, 0);
	
	// add all properties relevant to this node
	for (OperatorDescriptorSingle dps : getPossibleProperties()) {
		for (RequestedGlobalProperties gp : dps.getPossibleGlobalProperties()) {
			
			if (gp.getPartitioning().isPartitionedOnKey()) {
				// make sure that among the same partitioning types, we do not push anything down that has fewer key fields
				
				for (RequestedGlobalProperties contained : props.getGlobalProperties()) {
					if (contained.getPartitioning() == gp.getPartitioning() && gp.getPartitionedFields().isValidSubset(contained.getPartitionedFields())) {
						props.getGlobalProperties().remove(contained);
						break;
					}
				}
			}
			
			props.addGlobalProperties(gp);
		}
		
		for (RequestedLocalProperties lp : dps.getPossibleLocalProperties()) {
			props.addLocalProperties(lp);
		}
	}
	this.inConn.setInterestingProperties(props);
	
	for (DagConnection conn : getBroadcastConnections()) {
		conn.setInterestingProperties(new InterestingProperties());
	}
}
 

/**
 * Sets the interesting properties for this pact connection.
 * 
 * @param props The interesting properties.
 */
public void setInterestingProperties(InterestingProperties props) {
	if (this.interestingProps == null) {
		this.interestingProps = props;
	} else {
		throw new IllegalStateException("Interesting Properties have already been set.");
	}
}
 

@Override
public void computeInterestingPropertiesForInputs(CostEstimator estimator) {
	// get what we inherit and what is preserved by our user code 
	final InterestingProperties props1 = getInterestingProperties().filterByCodeAnnotations(this, 0);
	final InterestingProperties props2 = getInterestingProperties().filterByCodeAnnotations(this, 1);
	
	// add all properties relevant to this node
	for (OperatorDescriptorDual dpd : getProperties()) {
		for (GlobalPropertiesPair gp : dpd.getPossibleGlobalProperties()) {
			// input 1
			props1.addGlobalProperties(gp.getProperties1());
			
			// input 2
			props2.addGlobalProperties(gp.getProperties2());
		}
		for (LocalPropertiesPair lp : dpd.getPossibleLocalProperties()) {
			// input 1
			props1.addLocalProperties(lp.getProperties1());
			
			// input 2
			props2.addLocalProperties(lp.getProperties2());
		}
	}
	this.input1.setInterestingProperties(props1);
	this.input2.setInterestingProperties(props2);
	
	for (DagConnection conn : getBroadcastConnections()) {
		conn.setInterestingProperties(new InterestingProperties());
	}
}
 

/**
 * Computes all the interesting properties that are relevant to this node. The interesting
 * properties are a union of the interesting properties on each outgoing connection.
 * However, if two interesting properties on the outgoing connections overlap,
 * the interesting properties will occur only once in this set. For that, this
 * method deduplicates and merges the interesting properties.
 * This method returns copies of the original interesting properties objects and
 * leaves the original objects, contained by the connections, unchanged.
 */
public void computeUnionOfInterestingPropertiesFromSuccessors() {
	List<DagConnection> conns = getOutgoingConnections();
	if (conns.size() == 0) {
		// no incoming, we have none ourselves
		this.intProps = new InterestingProperties();
	} else {
		this.intProps = conns.get(0).getInterestingProperties().clone();
		for (int i = 1; i < conns.size(); i++) {
			this.intProps.addInterestingProperties(conns.get(i).getInterestingProperties());
		}
	}
	this.intProps.dropTrivials();
}
 

@Override
public void computeInterestingPropertiesForInputs(CostEstimator estimator) {
	// get what we inherit and what is preserved by our user code 
	final InterestingProperties props1 = getInterestingProperties().filterByCodeAnnotations(this, 0);
	final InterestingProperties props2 = getInterestingProperties().filterByCodeAnnotations(this, 1);
	
	// add all properties relevant to this node
	for (OperatorDescriptorDual dpd : getProperties()) {
		for (GlobalPropertiesPair gp : dpd.getPossibleGlobalProperties()) {
			// input 1
			props1.addGlobalProperties(gp.getProperties1());
			
			// input 2
			props2.addGlobalProperties(gp.getProperties2());
		}
		for (LocalPropertiesPair lp : dpd.getPossibleLocalProperties()) {
			// input 1
			props1.addLocalProperties(lp.getProperties1());
			
			// input 2
			props2.addLocalProperties(lp.getProperties2());
		}
	}
	this.input1.setInterestingProperties(props1);
	this.input2.setInterestingProperties(props2);
	
	for (DagConnection conn : getBroadcastConnections()) {
		conn.setInterestingProperties(new InterestingProperties());
	}
}
 

/**
 * Computes all the interesting properties that are relevant to this node. The interesting
 * properties are a union of the interesting properties on each outgoing connection.
 * However, if two interesting properties on the outgoing connections overlap,
 * the interesting properties will occur only once in this set. For that, this
 * method deduplicates and merges the interesting properties.
 * This method returns copies of the original interesting properties objects and
 * leaves the original objects, contained by the connections, unchanged.
 */
public void computeUnionOfInterestingPropertiesFromSuccessors() {
	List<DagConnection> conns = getOutgoingConnections();
	if (conns.size() == 0) {
		// no incoming, we have none ourselves
		this.intProps = new InterestingProperties();
	} else {
		this.intProps = conns.get(0).getInterestingProperties().clone();
		for (int i = 1; i < conns.size(); i++) {
			this.intProps.addInterestingProperties(conns.get(i).getInterestingProperties());
		}
	}
	this.intProps.dropTrivials();
}
 

/**
 * Sets the interesting properties for this pact connection.
 * 
 * @param props The interesting properties.
 */
public void setInterestingProperties(InterestingProperties props) {
	if (this.interestingProps == null) {
		this.interestingProps = props;
	} else {
		throw new IllegalStateException("Interesting Properties have already been set.");
	}
}
 

@Override
public void computeInterestingPropertiesForInputs(CostEstimator estimator) { 
	final InterestingProperties props = getInterestingProperties();
	
	// if no other properties exist, add the pruned trivials back
	if (props.getGlobalProperties().isEmpty()) {
		props.addGlobalProperties(new RequestedGlobalProperties());
	}
	props.addLocalProperties(new RequestedLocalProperties());
	this.input1.setInterestingProperties(props.clone());
	this.input2.setInterestingProperties(props.clone());
	
	this.channelProps = props.getGlobalProperties();
}
 

@Override
public void computeInterestingPropertiesForInputs(CostEstimator estimator) {
	// get what we inherit and what is preserved by our user code 
	final InterestingProperties props = getInterestingProperties().filterByCodeAnnotations(this, 0);
	
	// add all properties relevant to this node
	for (OperatorDescriptorSingle dps : getPossibleProperties()) {
		for (RequestedGlobalProperties gp : dps.getPossibleGlobalProperties()) {
			
			if (gp.getPartitioning().isPartitionedOnKey()) {
				// make sure that among the same partitioning types, we do not push anything down that has fewer key fields
				
				for (RequestedGlobalProperties contained : props.getGlobalProperties()) {
					if (contained.getPartitioning() == gp.getPartitioning() && gp.getPartitionedFields().isValidSubset(contained.getPartitionedFields())) {
						props.getGlobalProperties().remove(contained);
						break;
					}
				}
			}
			
			props.addGlobalProperties(gp);
		}
		
		for (RequestedLocalProperties lp : dps.getPossibleLocalProperties()) {
			props.addLocalProperties(lp);
		}
	}
	this.inConn.setInterestingProperties(props);
	
	for (DagConnection conn : getBroadcastConnections()) {
		conn.setInterestingProperties(new InterestingProperties());
	}
}
 

@Override
public void computeInterestingPropertiesForInputs(CostEstimator estimator) { 
	final InterestingProperties props = getInterestingProperties();
	
	// if no other properties exist, add the pruned trivials back
	if (props.getGlobalProperties().isEmpty()) {
		props.addGlobalProperties(new RequestedGlobalProperties());
	}
	props.addLocalProperties(new RequestedLocalProperties());
	this.input1.setInterestingProperties(props.clone());
	this.input2.setInterestingProperties(props.clone());
	
	this.channelProps = props.getGlobalProperties();
}
 

@Override
public void computeInterestingPropertiesForInputs(CostEstimator estimator) {
	// get what we inherit and what is preserved by our user code 
	final InterestingProperties props = getInterestingProperties().filterByCodeAnnotations(this, 0);
	
	// add all properties relevant to this node
	for (OperatorDescriptorSingle dps : getPossibleProperties()) {
		for (RequestedGlobalProperties gp : dps.getPossibleGlobalProperties()) {
			
			if (gp.getPartitioning().isPartitionedOnKey()) {
				// make sure that among the same partitioning types, we do not push anything down that has fewer key fields
				
				for (RequestedGlobalProperties contained : props.getGlobalProperties()) {
					if (contained.getPartitioning() == gp.getPartitioning() && gp.getPartitionedFields().isValidSubset(contained.getPartitionedFields())) {
						props.getGlobalProperties().remove(contained);
						break;
					}
				}
			}
			
			props.addGlobalProperties(gp);
		}
		
		for (RequestedLocalProperties lp : dps.getPossibleLocalProperties()) {
			props.addLocalProperties(lp);
		}
	}
	this.inConn.setInterestingProperties(props);
	
	for (DagConnection conn : getBroadcastConnections()) {
		conn.setInterestingProperties(new InterestingProperties());
	}
}
 

@Override
public void computeInterestingPropertiesForInputs(CostEstimator estimator) { 
	final InterestingProperties props = getInterestingProperties();
	
	// if no other properties exist, add the pruned trivials back
	if (props.getGlobalProperties().isEmpty()) {
		props.addGlobalProperties(new RequestedGlobalProperties());
	}
	props.addLocalProperties(new RequestedLocalProperties());
	this.input1.setInterestingProperties(props.clone());
	this.input2.setInterestingProperties(props.clone());
	
	this.channelProps = props.getGlobalProperties();
}
 

/**
 * Sets the interesting properties for this pact connection.
 * 
 * @param props The interesting properties.
 */
public void setInterestingProperties(InterestingProperties props) {
	if (this.interestingProps == null) {
		this.interestingProps = props;
	} else {
		throw new IllegalStateException("Interesting Properties have already been set.");
	}
}
 

@Override
public void computeInterestingPropertiesForInputs(CostEstimator estimator) {
	// get what we inherit and what is preserved by our user code 
	final InterestingProperties props1 = getInterestingProperties().filterByCodeAnnotations(this, 0);
	final InterestingProperties props2 = getInterestingProperties().filterByCodeAnnotations(this, 1);
	
	// add all properties relevant to this node
	for (OperatorDescriptorDual dpd : getProperties()) {
		for (GlobalPropertiesPair gp : dpd.getPossibleGlobalProperties()) {
			// input 1
			props1.addGlobalProperties(gp.getProperties1());
			
			// input 2
			props2.addGlobalProperties(gp.getProperties2());
		}
		for (LocalPropertiesPair lp : dpd.getPossibleLocalProperties()) {
			// input 1
			props1.addLocalProperties(lp.getProperties1());
			
			// input 2
			props2.addLocalProperties(lp.getProperties2());
		}
	}
	this.input1.setInterestingProperties(props1);
	this.input2.setInterestingProperties(props2);
	
	for (DagConnection conn : getBroadcastConnections()) {
		conn.setInterestingProperties(new InterestingProperties());
	}
}
 

/**
 * Computes all the interesting properties that are relevant to this node. The interesting
 * properties are a union of the interesting properties on each outgoing connection.
 * However, if two interesting properties on the outgoing connections overlap,
 * the interesting properties will occur only once in this set. For that, this
 * method deduplicates and merges the interesting properties.
 * This method returns copies of the original interesting properties objects and
 * leaves the original objects, contained by the connections, unchanged.
 */
public void computeUnionOfInterestingPropertiesFromSuccessors() {
	List<DagConnection> conns = getOutgoingConnections();
	if (conns.size() == 0) {
		// no incoming, we have none ourselves
		this.intProps = new InterestingProperties();
	} else {
		this.intProps = conns.get(0).getInterestingProperties().clone();
		for (int i = 1; i < conns.size(); i++) {
			this.intProps.addInterestingProperties(conns.get(i).getInterestingProperties());
		}
	}
	this.intProps.dropTrivials();
}
 

@Override
public void computeInterestingPropertiesForInputs(CostEstimator estimator) {
	final InterestingProperties intProps = getInterestingProperties().clone();
	
	if (this.terminationCriterion != null) {
		// first propagate through termination Criterion. since it has no successors, it has no
		// interesting properties
		this.terminationCriterionRootConnection.setInterestingProperties(new InterestingProperties());
		this.terminationCriterion.accept(new InterestingPropertyVisitor(estimator));
	}
	
	// we need to make 2 interesting property passes, because the root of the step function needs also
	// the interesting properties as generated by the partial solution
	
	// give our own interesting properties (as generated by the iterations successors) to the step function and
	// make the first pass
	this.rootConnection.setInterestingProperties(intProps);
	this.nextPartialSolution.accept(new InterestingPropertyVisitor(estimator));
	
	// take the interesting properties of the partial solution and add them to the root interesting properties
	InterestingProperties partialSolutionIntProps = this.partialSolution.getInterestingProperties();
	intProps.getGlobalProperties().addAll(partialSolutionIntProps.getGlobalProperties());
	intProps.getLocalProperties().addAll(partialSolutionIntProps.getLocalProperties());
	
	// clear all interesting properties to prepare the second traversal
	// this clears only the path down from the next partial solution. The paths down
	// from the termination criterion (before they meet the paths down from the next partial solution)
	// remain unaffected by this step
	this.rootConnection.clearInterestingProperties();
	this.nextPartialSolution.accept(InterestingPropertiesClearer.INSTANCE);
	
	// 2nd pass
	this.rootConnection.setInterestingProperties(intProps);
	this.nextPartialSolution.accept(new InterestingPropertyVisitor(estimator));
	
	// now add the interesting properties of the partial solution to the input
	final InterestingProperties inProps = this.partialSolution.getInterestingProperties().clone();
	inProps.addGlobalProperties(new RequestedGlobalProperties());
	inProps.addLocalProperties(new RequestedLocalProperties());
	this.inConn.setInterestingProperties(inProps);
}
 

@Override
public List<PlanNode> getAlternativePlans(CostEstimator estimator) {
	// check if we have a cached version
	if (this.cachedPlans != null) {
		return this.cachedPlans;
	}
	
	// calculate alternative sub-plans for predecessor
	List<? extends PlanNode> subPlans = getPredecessorNode().getAlternativePlans(estimator);
	List<PlanNode> outputPlans = new ArrayList<PlanNode>();
	
	final int parallelism = getParallelism();
	final int inDop = getPredecessorNode().getParallelism();

	final ExecutionMode executionMode = this.input.getDataExchangeMode();
	final boolean dopChange = parallelism != inDop;
	final boolean breakPipeline = this.input.isBreakingPipeline();

	InterestingProperties ips = this.input.getInterestingProperties();
	for (PlanNode p : subPlans) {
		for (RequestedGlobalProperties gp : ips.getGlobalProperties()) {
			for (RequestedLocalProperties lp : ips.getLocalProperties()) {
				Channel c = new Channel(p);
				gp.parameterizeChannel(c, dopChange, executionMode, breakPipeline);
				lp.parameterizeChannel(c);
				c.setRequiredLocalProps(lp);
				c.setRequiredGlobalProps(gp);
				
				// no need to check whether the created properties meet what we need in case
				// of ordering or global ordering, because the only interesting properties we have
				// are what we require
				outputPlans.add(new SinkPlanNode(this, "DataSink ("+this.getOperator().getName()+")" ,c));
			}
		}
	}
	
	// cost and prune the plans
	for (PlanNode node : outputPlans) {
		estimator.costOperator(node);
	}
	prunePlanAlternatives(outputPlans);

	this.cachedPlans = outputPlans;
	return outputPlans;
}
 

@Override
public void computeInterestingPropertiesForInputs(CostEstimator estimator) {
	// our own solution (the solution set) is always partitioned and this cannot be adjusted
	// depending on what the successor to the workset iteration requests. for that reason,
	// we ignore incoming interesting properties.
	
	// in addition, we need to make 2 interesting property passes, because the root of the step function 
	// that computes the next workset needs the interesting properties as generated by the
	// workset source of the step function. the second pass concerns only the workset path.
	// as initial interesting properties, we have the trivial ones for the step function,
	// and partitioned on the solution set key for the solution set delta 
	
	RequestedGlobalProperties partitionedProperties = new RequestedGlobalProperties();
	partitionedProperties.setHashPartitioned(this.solutionSetKeyFields);
	InterestingProperties partitionedIP = new InterestingProperties();
	partitionedIP.addGlobalProperties(partitionedProperties);
	partitionedIP.addLocalProperties(new RequestedLocalProperties());
	
	this.nextWorksetRootConnection.setInterestingProperties(new InterestingProperties());
	this.solutionSetDeltaRootConnection.setInterestingProperties(partitionedIP.clone());
	
	InterestingPropertyVisitor ipv = new InterestingPropertyVisitor(estimator);
	this.nextWorkset.accept(ipv);
	this.solutionSetDelta.accept(ipv);
	
	// take the interesting properties of the partial solution and add them to the root interesting properties
	InterestingProperties worksetIntProps = this.worksetNode.getInterestingProperties();
	InterestingProperties intProps = new InterestingProperties();
	intProps.getGlobalProperties().addAll(worksetIntProps.getGlobalProperties());
	intProps.getLocalProperties().addAll(worksetIntProps.getLocalProperties());
	
	// clear all interesting properties to prepare the second traversal
	this.nextWorksetRootConnection.clearInterestingProperties();
	this.nextWorkset.accept(InterestingPropertiesClearer.INSTANCE);
	
	// 2nd pass
	this.nextWorksetRootConnection.setInterestingProperties(intProps);
	this.nextWorkset.accept(ipv);
	
	// now add the interesting properties of the workset to the workset input
	final InterestingProperties inProps = this.worksetNode.getInterestingProperties().clone();
	inProps.addGlobalProperties(new RequestedGlobalProperties());
	inProps.addLocalProperties(new RequestedLocalProperties());
	this.input2.setInterestingProperties(inProps);
	
	// the partial solution must be hash partitioned, so it has only that as interesting properties
	this.input1.setInterestingProperties(partitionedIP);
}
 

@Override
public void computeInterestingPropertiesForInputs(CostEstimator estimator) {
	final InterestingProperties intProps = getInterestingProperties().clone();
	
	if (this.terminationCriterion != null) {
		// first propagate through termination Criterion. since it has no successors, it has no
		// interesting properties
		this.terminationCriterionRootConnection.setInterestingProperties(new InterestingProperties());
		this.terminationCriterion.accept(new InterestingPropertyVisitor(estimator));
	}
	
	// we need to make 2 interesting property passes, because the root of the step function needs also
	// the interesting properties as generated by the partial solution
	
	// give our own interesting properties (as generated by the iterations successors) to the step function and
	// make the first pass
	this.rootConnection.setInterestingProperties(intProps);
	this.nextPartialSolution.accept(new InterestingPropertyVisitor(estimator));
	
	// take the interesting properties of the partial solution and add them to the root interesting properties
	InterestingProperties partialSolutionIntProps = this.partialSolution.getInterestingProperties();
	intProps.getGlobalProperties().addAll(partialSolutionIntProps.getGlobalProperties());
	intProps.getLocalProperties().addAll(partialSolutionIntProps.getLocalProperties());
	
	// clear all interesting properties to prepare the second traversal
	// this clears only the path down from the next partial solution. The paths down
	// from the termination criterion (before they meet the paths down from the next partial solution)
	// remain unaffected by this step
	this.rootConnection.clearInterestingProperties();
	this.nextPartialSolution.accept(InterestingPropertiesClearer.INSTANCE);
	
	// 2nd pass
	this.rootConnection.setInterestingProperties(intProps);
	this.nextPartialSolution.accept(new InterestingPropertyVisitor(estimator));
	
	// now add the interesting properties of the partial solution to the input
	final InterestingProperties inProps = this.partialSolution.getInterestingProperties().clone();
	inProps.addGlobalProperties(new RequestedGlobalProperties());
	inProps.addLocalProperties(new RequestedLocalProperties());
	this.inConn.setInterestingProperties(inProps);
}
 

@Override
public void computeInterestingPropertiesForInputs(CostEstimator estimator) {
	// our own solution (the solution set) is always partitioned and this cannot be adjusted
	// depending on what the successor to the workset iteration requests. for that reason,
	// we ignore incoming interesting properties.
	
	// in addition, we need to make 2 interesting property passes, because the root of the step function 
	// that computes the next workset needs the interesting properties as generated by the
	// workset source of the step function. the second pass concerns only the workset path.
	// as initial interesting properties, we have the trivial ones for the step function,
	// and partitioned on the solution set key for the solution set delta 
	
	RequestedGlobalProperties partitionedProperties = new RequestedGlobalProperties();
	partitionedProperties.setHashPartitioned(this.solutionSetKeyFields);
	InterestingProperties partitionedIP = new InterestingProperties();
	partitionedIP.addGlobalProperties(partitionedProperties);
	partitionedIP.addLocalProperties(new RequestedLocalProperties());
	
	this.nextWorksetRootConnection.setInterestingProperties(new InterestingProperties());
	this.solutionSetDeltaRootConnection.setInterestingProperties(partitionedIP.clone());
	
	InterestingPropertyVisitor ipv = new InterestingPropertyVisitor(estimator);
	this.nextWorkset.accept(ipv);
	this.solutionSetDelta.accept(ipv);
	
	// take the interesting properties of the partial solution and add them to the root interesting properties
	InterestingProperties worksetIntProps = this.worksetNode.getInterestingProperties();
	InterestingProperties intProps = new InterestingProperties();
	intProps.getGlobalProperties().addAll(worksetIntProps.getGlobalProperties());
	intProps.getLocalProperties().addAll(worksetIntProps.getLocalProperties());
	
	// clear all interesting properties to prepare the second traversal
	this.nextWorksetRootConnection.clearInterestingProperties();
	this.nextWorkset.accept(InterestingPropertiesClearer.INSTANCE);
	
	// 2nd pass
	this.nextWorksetRootConnection.setInterestingProperties(intProps);
	this.nextWorkset.accept(ipv);
	
	// now add the interesting properties of the workset to the workset input
	final InterestingProperties inProps = this.worksetNode.getInterestingProperties().clone();
	inProps.addGlobalProperties(new RequestedGlobalProperties());
	inProps.addLocalProperties(new RequestedLocalProperties());
	this.input2.setInterestingProperties(inProps);
	
	// the partial solution must be hash partitioned, so it has only that as interesting properties
	this.input1.setInterestingProperties(partitionedIP);
}
 

@Override
public List<PlanNode> getAlternativePlans(CostEstimator estimator) {
	// check if we have a cached version
	if (this.cachedPlans != null) {
		return this.cachedPlans;
	}
	
	// calculate alternative sub-plans for predecessor
	List<? extends PlanNode> subPlans = getPredecessorNode().getAlternativePlans(estimator);
	List<PlanNode> outputPlans = new ArrayList<PlanNode>();
	
	final int parallelism = getParallelism();
	final int inDop = getPredecessorNode().getParallelism();

	final ExecutionMode executionMode = this.input.getDataExchangeMode();
	final boolean dopChange = parallelism != inDop;
	final boolean breakPipeline = this.input.isBreakingPipeline();

	InterestingProperties ips = this.input.getInterestingProperties();
	for (PlanNode p : subPlans) {
		for (RequestedGlobalProperties gp : ips.getGlobalProperties()) {
			for (RequestedLocalProperties lp : ips.getLocalProperties()) {
				Channel c = new Channel(p);
				gp.parameterizeChannel(c, dopChange, executionMode, breakPipeline);
				lp.parameterizeChannel(c);
				c.setRequiredLocalProps(lp);
				c.setRequiredGlobalProps(gp);
				
				// no need to check whether the created properties meet what we need in case
				// of ordering or global ordering, because the only interesting properties we have
				// are what we require
				outputPlans.add(new SinkPlanNode(this, "DataSink ("+this.getOperator().getName()+")" ,c));
			}
		}
	}
	
	// cost and prune the plans
	for (PlanNode node : outputPlans) {
		estimator.costOperator(node);
	}
	prunePlanAlternatives(outputPlans);

	this.cachedPlans = outputPlans;
	return outputPlans;
}
 

@Override
public void computeInterestingPropertiesForInputs(CostEstimator estimator) {
	final InterestingProperties intProps = getInterestingProperties().clone();
	
	if (this.terminationCriterion != null) {
		// first propagate through termination Criterion. since it has no successors, it has no
		// interesting properties
		this.terminationCriterionRootConnection.setInterestingProperties(new InterestingProperties());
		this.terminationCriterion.accept(new InterestingPropertyVisitor(estimator));
	}
	
	// we need to make 2 interesting property passes, because the root of the step function needs also
	// the interesting properties as generated by the partial solution
	
	// give our own interesting properties (as generated by the iterations successors) to the step function and
	// make the first pass
	this.rootConnection.setInterestingProperties(intProps);
	this.nextPartialSolution.accept(new InterestingPropertyVisitor(estimator));
	
	// take the interesting properties of the partial solution and add them to the root interesting properties
	InterestingProperties partialSolutionIntProps = this.partialSolution.getInterestingProperties();
	intProps.getGlobalProperties().addAll(partialSolutionIntProps.getGlobalProperties());
	intProps.getLocalProperties().addAll(partialSolutionIntProps.getLocalProperties());
	
	// clear all interesting properties to prepare the second traversal
	// this clears only the path down from the next partial solution. The paths down
	// from the termination criterion (before they meet the paths down from the next partial solution)
	// remain unaffected by this step
	this.rootConnection.clearInterestingProperties();
	this.nextPartialSolution.accept(InterestingPropertiesClearer.INSTANCE);
	
	// 2nd pass
	this.rootConnection.setInterestingProperties(intProps);
	this.nextPartialSolution.accept(new InterestingPropertyVisitor(estimator));
	
	// now add the interesting properties of the partial solution to the input
	final InterestingProperties inProps = this.partialSolution.getInterestingProperties().clone();
	inProps.addGlobalProperties(new RequestedGlobalProperties());
	inProps.addLocalProperties(new RequestedLocalProperties());
	this.inConn.setInterestingProperties(inProps);
}
 

@Override
public void computeInterestingPropertiesForInputs(CostEstimator estimator) {
	// our own solution (the solution set) is always partitioned and this cannot be adjusted
	// depending on what the successor to the workset iteration requests. for that reason,
	// we ignore incoming interesting properties.
	
	// in addition, we need to make 2 interesting property passes, because the root of the step function 
	// that computes the next workset needs the interesting properties as generated by the
	// workset source of the step function. the second pass concerns only the workset path.
	// as initial interesting properties, we have the trivial ones for the step function,
	// and partitioned on the solution set key for the solution set delta 
	
	RequestedGlobalProperties partitionedProperties = new RequestedGlobalProperties();
	partitionedProperties.setHashPartitioned(this.solutionSetKeyFields);
	InterestingProperties partitionedIP = new InterestingProperties();
	partitionedIP.addGlobalProperties(partitionedProperties);
	partitionedIP.addLocalProperties(new RequestedLocalProperties());
	
	this.nextWorksetRootConnection.setInterestingProperties(new InterestingProperties());
	this.solutionSetDeltaRootConnection.setInterestingProperties(partitionedIP.clone());
	
	InterestingPropertyVisitor ipv = new InterestingPropertyVisitor(estimator);
	this.nextWorkset.accept(ipv);
	this.solutionSetDelta.accept(ipv);
	
	// take the interesting properties of the partial solution and add them to the root interesting properties
	InterestingProperties worksetIntProps = this.worksetNode.getInterestingProperties();
	InterestingProperties intProps = new InterestingProperties();
	intProps.getGlobalProperties().addAll(worksetIntProps.getGlobalProperties());
	intProps.getLocalProperties().addAll(worksetIntProps.getLocalProperties());
	
	// clear all interesting properties to prepare the second traversal
	this.nextWorksetRootConnection.clearInterestingProperties();
	this.nextWorkset.accept(InterestingPropertiesClearer.INSTANCE);
	
	// 2nd pass
	this.nextWorksetRootConnection.setInterestingProperties(intProps);
	this.nextWorkset.accept(ipv);
	
	// now add the interesting properties of the workset to the workset input
	final InterestingProperties inProps = this.worksetNode.getInterestingProperties().clone();
	inProps.addGlobalProperties(new RequestedGlobalProperties());
	inProps.addLocalProperties(new RequestedLocalProperties());
	this.input2.setInterestingProperties(inProps);
	
	// the partial solution must be hash partitioned, so it has only that as interesting properties
	this.input1.setInterestingProperties(partitionedIP);
}
 

@Override
public List<PlanNode> getAlternativePlans(CostEstimator estimator) {
	// check if we have a cached version
	if (this.cachedPlans != null) {
		return this.cachedPlans;
	}
	
	// calculate alternative sub-plans for predecessor
	List<? extends PlanNode> subPlans = getPredecessorNode().getAlternativePlans(estimator);
	List<PlanNode> outputPlans = new ArrayList<PlanNode>();
	
	final int parallelism = getParallelism();
	final int inDop = getPredecessorNode().getParallelism();

	final ExecutionMode executionMode = this.input.getDataExchangeMode();
	final boolean dopChange = parallelism != inDop;
	final boolean breakPipeline = this.input.isBreakingPipeline();

	InterestingProperties ips = this.input.getInterestingProperties();
	for (PlanNode p : subPlans) {
		for (RequestedGlobalProperties gp : ips.getGlobalProperties()) {
			for (RequestedLocalProperties lp : ips.getLocalProperties()) {
				Channel c = new Channel(p);
				gp.parameterizeChannel(c, dopChange, executionMode, breakPipeline);
				lp.parameterizeChannel(c);
				c.setRequiredLocalProps(lp);
				c.setRequiredGlobalProps(gp);
				
				// no need to check whether the created properties meet what we need in case
				// of ordering or global ordering, because the only interesting properties we have
				// are what we require
				outputPlans.add(new SinkPlanNode(this, "DataSink ("+this.getOperator().getName()+")" ,c));
			}
		}
	}
	
	// cost and prune the plans
	for (PlanNode node : outputPlans) {
		estimator.costOperator(node);
	}
	prunePlanAlternatives(outputPlans);

	this.cachedPlans = outputPlans;
	return outputPlans;
}
 

/**
 * Gets the properties that are interesting for this node to produce.
 * 
 * @return The interesting properties for this node, or null, if not yet computed.
 */
public InterestingProperties getInterestingProperties() {
	return this.intProps;
}
 

/**
 * Gets the interesting properties object for this pact connection.
 * If the interesting properties for this connections have not yet been set,
 * this method returns null.
 * 
 * @return The collection of all interesting properties, or null, if they have not yet been set.
 */
public InterestingProperties getInterestingProperties() {
	return this.interestingProps;
}
 

/**
 * Gets the interesting properties object for this pact connection.
 * If the interesting properties for this connections have not yet been set,
 * this method returns null.
 * 
 * @return The collection of all interesting properties, or null, if they have not yet been set.
 */
public InterestingProperties getInterestingProperties() {
	return this.interestingProps;
}