org.apache.sysds.runtime.compress.cost

Interface ICostEstimate

All Superinterfaces:

Serializable

All Known Implementing Classes:

ComputationCostEstimator, DistinctCostEstimator, HybridCostEstimator, MemoryCostEstimator

public interface ICostEstimate
extends Serializable

A cost estimator interface. Cost here is either memory based or computation based. It is used to estimate the cost of a specific compression layout.

Field Summary

Fields

Modifier and Type	Field and Description
static org.apache.commons.logging.Log	LOG
static long	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.

Field Detail

serialVersionUID

static final long serialVersionUID

See Also:

Constant Field Values

LOG

static final org.apache.commons.logging.Log LOG

Method Detail

getUncompressedCost

double getUncompressedCost(CompressedSizeInfoColGroup g)

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.

Parameters:

g - A potential column group to compare to.

Returns:

The uncompressed cost.

getCostOfColumnGroup

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.

Parameters:

g - Column group to estimate the cost of

Returns:

The Cost of this column group

shouldAnalyze

boolean shouldAnalyze(CompressedSizeInfoColGroup g1,
                      CompressedSizeInfoColGroup g2)

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.

Parameters:

g1 - Group 1

g2 - Group 2

Returns:

If the joining should be analyzed.