Package 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 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	Description
TypeFilterCountProperty()

Method Summary

Modifier and Type	Method	Description
static int	evaluate(RelationalExpression expression)
Integer	evaluateAtExpression(RelationalExpression 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 RelationalExpression> ref, List<Integer> memberResults)	Evaluate the property at the given reference, using the results of evaluating the property at its members.

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.apple.foundationdb.record.query.plan.temp.PlannerProperty

evaluateAtQuantifier, shouldVisit, shouldVisit, shouldVisit

Constructor Detail

TypeFilterCountProperty

public TypeFilterCountProperty()

Method Detail

evaluateAtExpression

@Nonnull
public Integer evaluateAtExpression(@Nonnull
                                    RelationalExpression 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 graph in visit post-order of the depth-first traversal of the graph. That is, as each expression is visited (after all of its children have been visited, if applicable), evaluateAtExpression() is called on that expression.

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 RelationalExpression> 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 graph in visit post-order of the depth-first traversal of the graph. That is, as each reference is visited (after all of its members have been visited, if applicable), evaluateAtRef() is called on that reference.

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
                           RelationalExpression expression)