org.modeshape.jcr.query.optimize
Class RemoveEmptyAccessNodes

java.lang.Object
  org.modeshape.jcr.query.optimize.RemoveEmptyAccessNodes

All Implemented Interfaces:

OptimizerRule

@Immutable
public class RemoveEmptyAccessNodes
extends Object
implements OptimizerRule

An optimizer rule that removes any ACCESS nodes that are known to never return any tuples because of conflicting constraints.

Field Summary

static RemoveEmptyAccessNodes

INSTANCE

Constructor Summary

RemoveEmptyAccessNodes()

Method Summary

PlanNode	execute(QueryContext context, PlanNode plan, LinkedList<OptimizerRule> ruleStack) Optimize the supplied plan using the supplied context, hints, and yet-to-be-run rules.
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

INSTANCE

public static final RemoveEmptyAccessNodes INSTANCE

Constructor Detail

RemoveEmptyAccessNodes

public RemoveEmptyAccessNodes()

Method Detail

execute

public PlanNode execute(QueryContext context,
                        PlanNode plan,
                        LinkedList<OptimizerRule> ruleStack)

Description copied from interface: OptimizerRule

Optimize the supplied plan using the supplied context, hints, and yet-to-be-run rules.

Specified by:

execute in interface OptimizerRule

Parameters:

context - the context in which the query is being optimized; never null

plan - the plan to be optimized; never null

ruleStack - the stack of rules that will be run after this rule; never null

Returns:

the optimized plan; never null

toString

public String toString()

Overrides:

toString in class Object