org.apache.derby.impl.sql.compile
Class CostEstimateImpl

java.lang.Object
  org.apache.derby.impl.sql.compile.CostEstimateImpl

All Implemented Interfaces:

CostEstimate, StoreCostResult

Direct Known Subclasses:

Level2CostEstimateImpl

public class CostEstimateImpl
extends java.lang.Object
implements CostEstimate

Field Summary

double	cost
double	rowCount
double	singleScanRowCount

Constructor Summary

CostEstimateImpl()

CostEstimateImpl(double theCost, double theRowCount, double theSingleScanRowCount)

Method Summary

CostEstimate	add(CostEstimate other, CostEstimate retval) Add this cost estimate to another one.
CostEstimate	cloneMe() Get a copy of this CostEstimate
double	compare(CostEstimate other) Compare this cost estimate with the given cost estimate.
CostEstimate	divide(double divisor, CostEstimate retval) Divide this cost estimate by a scalar, non-dimensional number.
double	getEstimatedCost() Get the estimated cost.
long	getEstimatedRowCount() Get the estimated row count.
boolean	isUninitialized() Return whether or not this CostEstimate is uninitialized.
CostEstimate	multiply(double multiplicand, CostEstimate retval) Multiply this cost estimate by a scalar, non-dimensional number.
double	rowCount() Get the estimated number of rows returned by the ResultSet that this CostEstimate models.
void	setCost(CostEstimate other) Copy the values from the given cost estimate into this one.
void	setCost(double cost, double rowCount, double singleScanRowCount) Set the cost for this cost estimate.
void	setEstimatedCost(double cost) Set the estimated cost.
void	setEstimatedRowCount(long count) Set the estimated row count.
void	setSingleScanRowCount(double singleScanRowCount) Set the single scan row count.
CostEstimateImpl	setState(double theCost, double theRowCount, CostEstimateImpl retval)
double	singleScanRowCount() Get the estimated number of rows returned by a single scan of the ResultSet that this CostEstimate models.

Methods inherited from class java.lang.Object

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

Field Detail

cost

public double cost

rowCount

public double rowCount

singleScanRowCount

public double singleScanRowCount

Constructor Detail

CostEstimateImpl

public CostEstimateImpl()

CostEstimateImpl

public CostEstimateImpl(double theCost,
                        double theRowCount,
                        double theSingleScanRowCount)

Method Detail

setCost

public void setCost(double cost,
                    double rowCount,
                    double singleScanRowCount)

Description copied from interface: CostEstimate

Set the cost for this cost estimate.

Specified by:

setCost in interface CostEstimate

See Also:

CostEstimate.setCost(double, double, double)

setCost

public void setCost(CostEstimate other)

Description copied from interface: CostEstimate

Copy the values from the given cost estimate into this one.

Specified by:

setCost in interface CostEstimate

See Also:

CostEstimate.setCost(double, double, double)

setSingleScanRowCount

public void setSingleScanRowCount(double singleScanRowCount)

Description copied from interface: CostEstimate

Set the single scan row count.

Specified by:

setSingleScanRowCount in interface CostEstimate

See Also:

CostEstimate.setSingleScanRowCount(double)

compare

public double compare(CostEstimate other)

Description copied from interface: CostEstimate

Compare this cost estimate with the given cost estimate.

Specified by:

compare in interface CostEstimate

Parameters:

other - The cost estimate to compare this one with

Returns:

< 0 if this < other, 0 if this == other, > 0 if this > other

See Also:

CostEstimate.compare(org.apache.derby.iapi.sql.compile.CostEstimate)

add

public CostEstimate add(CostEstimate other,
                        CostEstimate retval)

Description copied from interface: CostEstimate

Add this cost estimate to another one. This presumes that any row ordering is destroyed.

Specified by:

add in interface CostEstimate

Parameters:

other - This cost estimate to add this one to.

retval - If non-null, put the result here.

Returns:

this + other.

See Also:

CostEstimate.add(org.apache.derby.iapi.sql.compile.CostEstimate, org.apache.derby.iapi.sql.compile.CostEstimate)

multiply

public CostEstimate multiply(double multiplicand,
                             CostEstimate retval)

Description copied from interface: CostEstimate

Multiply this cost estimate by a scalar, non-dimensional number. This presumes that any row ordering is destroyed.

Specified by:

multiply in interface CostEstimate

Parameters:

multiplicand - The value to multiply this CostEstimate by.

retval - If non-null, put the result here.

Returns:

this * multiplicand

See Also:

CostEstimate.multiply(double, org.apache.derby.iapi.sql.compile.CostEstimate)

divide

public CostEstimate divide(double divisor,
                           CostEstimate retval)

Description copied from interface: CostEstimate

Divide this cost estimate by a scalar, non-dimensional number.

Specified by:

divide in interface CostEstimate

Parameters:

divisor - The value to divide this CostEstimate by.

retval - If non-null, put the result here.

Returns:

this / divisor

See Also:

CostEstimate.divide(double, org.apache.derby.iapi.sql.compile.CostEstimate)

rowCount

public double rowCount()

Description copied from interface: CostEstimate

Get the estimated number of rows returned by the ResultSet that this CostEstimate models.

Specified by:

rowCount in interface CostEstimate

See Also:

CostEstimate.rowCount()

singleScanRowCount

public double singleScanRowCount()

Description copied from interface: CostEstimate

Get the estimated number of rows returned by a single scan of the ResultSet that this CostEstimate models.

Specified by:

singleScanRowCount in interface CostEstimate

See Also:

CostEstimate.singleScanRowCount()

cloneMe

public CostEstimate cloneMe()

Description copied from interface: CostEstimate

Get a copy of this CostEstimate

Specified by:

cloneMe in interface CostEstimate

See Also:

CostEstimate.cloneMe()

isUninitialized

public boolean isUninitialized()

Description copied from interface: CostEstimate

Return whether or not this CostEstimate is uninitialized.

Specified by:

isUninitialized in interface CostEstimate

Returns:

Whether or not this CostEstimate is uninitialized.

See Also:

CostEstimate.isUninitialized()

getEstimatedCost

public double getEstimatedCost()

Description copied from interface: StoreCostResult

Get the estimated cost.

Specified by:

getEstimatedCost in interface StoreCostResult

See Also:

StoreCostResult.getEstimatedCost()

setEstimatedCost

public void setEstimatedCost(double cost)

Description copied from interface: StoreCostResult

Set the estimated cost.

Specified by:

setEstimatedCost in interface StoreCostResult

See Also:

StoreCostResult.setEstimatedCost(double)

getEstimatedRowCount

public long getEstimatedRowCount()

Description copied from interface: StoreCostResult

Get the estimated row count.

Specified by:

getEstimatedRowCount in interface StoreCostResult

See Also:

StoreCostResult.getEstimatedRowCount()

setEstimatedRowCount

public void setEstimatedRowCount(long count)

Description copied from interface: StoreCostResult

Set the estimated row count.

Specified by:

setEstimatedRowCount in interface StoreCostResult

See Also:

StoreCostResult.setEstimatedRowCount(long)

setState

public CostEstimateImpl setState(double theCost,
                                 double theRowCount,
                                 CostEstimateImpl retval)