com.metamatrix.query.optimizer.relational.rules
Class NewCalculateCostUtil

java.lang.Object
  com.metamatrix.query.optimizer.relational.rules.NewCalculateCostUtil

public class NewCalculateCostUtil
extends java.lang.Object

Since:

4.3

Field Summary

static int	DEFAULT_STRONG_COST
static float	UNKNOWN_VALUE

Constructor Summary

NewCalculateCostUtil()

Method Summary

static float

computeCostForDepJoin(PlanNode joinNode, boolean leftIndependent, JoinNode.JoinStrategyType joinStrategy, QueryMetadataInterface metadata, CapabilitiesFinder capFinder, CommandContext context) Computes the cost of a Dependent Join The worst possible cost will arise from a high independent ndv (many dependent sets) and a low depenendent ndv (possibly many matches per set) This logic uses the same assumption as criteria in that ndv is used as a divisor of cardinality.

static float

computeCostForJoin(PlanNode leftChildNode, PlanNode rightChildNode, JoinNode.JoinStrategyType joinStrategy, QueryMetadataInterface metadata, CommandContext context) Computes the cost of a Merge Join

Methods inherited from class java.lang.Object

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

Field Detail

UNKNOWN_VALUE

public static final float UNKNOWN_VALUE

See Also:

Constant Field Values

DEFAULT_STRONG_COST

public static final int DEFAULT_STRONG_COST

See Also:

Constant Field Values

Constructor Detail

NewCalculateCostUtil

public NewCalculateCostUtil()

Method Detail

computeCostForJoin

public static float computeCostForJoin(PlanNode leftChildNode,
                                       PlanNode rightChildNode,
                                       JoinNode.JoinStrategyType joinStrategy,
                                       QueryMetadataInterface metadata,
                                       CommandContext context)
                                throws MetaMatrixComponentException,
                                       QueryMetadataException

Computes the cost of a Merge Join

Throws:

MetaMatrixComponentException

QueryMetadataException

computeCostForDepJoin

public static float computeCostForDepJoin(PlanNode joinNode,
                                          boolean leftIndependent,
                                          JoinNode.JoinStrategyType joinStrategy,
                                          QueryMetadataInterface metadata,
                                          CapabilitiesFinder capFinder,
                                          CommandContext context)
                                   throws MetaMatrixComponentException,
                                          QueryMetadataException

Computes the cost of a Dependent Join The worst possible cost will arise from a high independent ndv (many dependent sets) and a low depenendent ndv (possibly many matches per set) This logic uses the same assumption as criteria in that ndv is used as a divisor of cardinality.

Throws:

MetaMatrixComponentException

QueryMetadataException