org.apache.sysds.runtime.compress.cost

Class HybridCostEstimator

java.lang.Object

org.apache.sysds.runtime.compress.cost.HybridCostEstimator

All Implemented Interfaces:

Serializable, ICostEstimate

public class HybridCostEstimator
extends Object
implements ICostEstimate

See Also:

Serialized Form

Field Summary

Fields inherited from interface org.apache.sysds.runtime.compress.cost.ICostEstimate

LOG, serialVersionUID

Method Summary

Modifier and Type	Method and Description
double	getCostOfColumnGroup(CompressedSizeInfoColGroup g) If the instruction does not care about the inter column group cost, such as in memory cost or in computation cost of right or left matrix multiplication we simply estimate the cost of individual column groups.
double	getUncompressedCost(CompressedSizeInfoColGroup g) Calculate the cost of execution if uncompressed.
boolean	shouldAnalyze(CompressedSizeInfoColGroup g1, CompressedSizeInfoColGroup g2) Decide if the column groups should be analysed, or the worst case join should be expected.

Methods inherited from class java.lang.Object

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

Method Detail

getUncompressedCost

public double getUncompressedCost(CompressedSizeInfoColGroup g)

Description copied from interface: ICostEstimate

Calculate the cost of execution if uncompressed. This is used as an optimization goal to at least achieve, since if the uncompressed cost of calculation is lower than in compressed space we don't want to compress.

Specified by:

getUncompressedCost in interface ICostEstimate

Parameters:

g - A potential column group to compare to.

Returns:

The uncompressed cost.

getCostOfColumnGroup

public double getCostOfColumnGroup(CompressedSizeInfoColGroup g)

Description copied from interface: ICostEstimate

If the instruction does not care about the inter column group cost, such as in memory cost or in computation cost of right or left matrix multiplication we simply estimate the cost of individual column groups.

Specified by:

getCostOfColumnGroup in interface ICostEstimate

Parameters:

g - Column group to estimate the cost of

Returns:

The Cost of this column group

shouldAnalyze

public boolean shouldAnalyze(CompressedSizeInfoColGroup g1,
                             CompressedSizeInfoColGroup g2)

Description copied from interface: ICostEstimate

Decide if the column groups should be analysed, or the worst case join should be expected. This is use full if the column groups are very small and the in practice difference between joining or not is small. Or in the other case where there is some obvious reason why these two groups does not fit together.

Specified by:

shouldAnalyze in interface ICostEstimate

Parameters:

g1 - Group 1

g2 - Group 2

Returns:

If the joining should be analyzed.