com.apple.foundationdb.record.query.plan.temp.properties

Class TypeFilterCountProperty

java.lang.Object

com.apple.foundationdb.record.query.plan.temp.properties.TypeFilterCountProperty

All Implemented Interfaces:

PlannerProperty<Integer>

public class TypeFilterCountProperty
extends Object
implements PlannerProperty<Integer>

A property that determines the sum, over all elements of a PlannerExpression tree, of the number of record types that are passed by type filters in the tree. Records that are filtered for on more than one type filter are not de-duplicated. For example, if there are two TypeFilterExpressions, one that filters for records of types Type1 or Type2 and one that filters for records of type Type1, then this property would evaluate to 3.

This property provides some heuristic sense of how much work is being done by type filters, since unnecessary ones are aggressively pruned by the planner.

Constructor Summary

Constructors

Constructor and Description
TypeFilterCountProperty()

Method Summary

Modifier and Type	Method and Description
static int	evaluate(PlannerExpression expression)
Integer	evaluateAtExpression(PlannerExpression expression, List<Integer> childResults) Evaluate the property at the given expression, using the results of evaluating the property at its children.
Integer	evaluateAtRef(ExpressionRef<? extends PlannerExpression> ref, List<Integer> memberResults) Evaluate the property at the given reference, using the results of evaluating the property at its members.
boolean	shouldVisit(ExpressionRef<? extends PlannerExpression> ref) Return whether the property should visit the subtree rooted at the given expression.
boolean	shouldVisit(PlannerExpression expression) Return whether the property should visit the subtree rooted at the given expression.

Methods inherited from class java.lang.Object

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

Constructor Detail

TypeFilterCountProperty

public TypeFilterCountProperty()

Method Detail

shouldVisit

public boolean shouldVisit(@Nonnull
                           ExpressionRef<? extends PlannerExpression> ref)

Description copied from interface: PlannerProperty

Return whether the property should visit the subtree rooted at the given expression. Called on nodes in the expression tree in visit pre-order of the depth-first traversal of the tree. That is, as each node is visited for the first time, shouldVisit() is called on that node. If shouldVisit() returns false, then PlannerProperty.evaluateAtRef(ExpressionRef, List) will not be called on the given expression.

Specified by:

shouldVisit in interface PlannerProperty<Integer>

Parameters:

ref - the expression reference to visit

Returns:

true if the members of ref should be visited and false if they should not be visited

shouldVisit

public boolean shouldVisit(@Nonnull
                           PlannerExpression expression)

Description copied from interface: PlannerProperty

Return whether the property should visit the subtree rooted at the given expression. Called on nodes in the expression tree in visit pre-order of the depth-first traversal of the tree. That is, as each node is visited for the first time, shouldVisit() is called on that node. If shouldVisit() returns false, then PlannerProperty.evaluateAtExpression(PlannerExpression, List) will not be called on the given expression.

Specified by:

shouldVisit in interface PlannerProperty<Integer>

Parameters:

expression - the planner expression to visit

Returns:

true if the children of expression should be visited and false if they should not be visited

evaluateAtExpression

@Nonnull
public Integer evaluateAtExpression(@Nonnull
                                             PlannerExpression expression,
                                             @Nonnull
                                             List<Integer> childResults)

Description copied from interface: PlannerProperty

Evaluate the property at the given expression, using the results of evaluating the property at its children. Called on nodes in the expression tree in visit post-order of the depth-first traversal of the tree. That is, as each node is visited for the last time (after all of its children have been visited, if applicable), evaluateAtExpression() is called on that node.

Specified by:

evaluateAtExpression in interface PlannerProperty<Integer>

Parameters:

expression - the cursor to visit

childResults - the results of the property evaluated at the children of expression

Returns:

the value of property at the given expression

evaluateAtRef

@Nonnull
public Integer evaluateAtRef(@Nonnull
                                      ExpressionRef<? extends PlannerExpression> ref,
                                      @Nonnull
                                      List<Integer> memberResults)

Description copied from interface: PlannerProperty

Evaluate the property at the given reference, using the results of evaluating the property at its members. Called on nodes in the expression tree in visit post-order of the depth-first traversal of the tree. That is, as each node is visited for the last time (after all of its children have been visited, if applicable), evaluateAtRef() is called on that node.

Specified by:

evaluateAtRef in interface PlannerProperty<Integer>

Parameters:

ref - the expression reference to visit

memberResults - the results of the property evaluated at the members of ref

Returns:

the value of property at the given reference

evaluate

public static int evaluate(@Nonnull
                           PlannerExpression expression)