Package org.apache.sysds.runtime.compress.estim

Class ComEstExact

java.lang.Object

org.apache.sysds.runtime.compress.estim.AComEst

org.apache.sysds.runtime.compress.estim.ComEstExact

public class ComEstExact
extends AComEst

Exact compressed size estimator (examines entire dataset).

Constructor Summary

Constructors

Constructor	Description
ComEstExact(MatrixBlock data, CompressionSettings compSettings)

Method Summary

Modifier and Type	Method	Description
CompressedSizeInfoColGroup	getColGroupInfo(IColIndex colIndexes, int estimate, int nrUniqueUpperBound)	A method to extract the Compressed Size Info for a given list of columns, This method further limits the estimated number of unique values, since in some cases the estimated number of uniques is estimated higher than the number estimated in sub groups of the given colIndexes.
CompressedSizeInfoColGroup	getDeltaColGroupInfo(IColIndex colIndexes, int estimate, int nrUniqueUpperBound)	A method to extract the Compressed Size Info for a given list of columns, This method further limits the estimated number of unique values, since in some cases the estimated number of uniques is estimated higher than the number estimated in sub groups of the given colIndexes.

Methods inherited from class org.apache.sysds.runtime.compress.estim.AComEst

clearNNZ, combine, combine, computeCompressedSizeInfos, getColGroupInfo, getDeltaColGroupInfo, getNumColumns, getNumRows, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

ComEstExact

public ComEstExact(MatrixBlock data,
                   CompressionSettings compSettings)

Method Detail

getColGroupInfo

public CompressedSizeInfoColGroup getColGroupInfo(IColIndex colIndexes,
                                                  int estimate,
                                                  int nrUniqueUpperBound)

Description copied from class: AComEst

A method to extract the Compressed Size Info for a given list of columns, This method further limits the estimated number of unique values, since in some cases the estimated number of uniques is estimated higher than the number estimated in sub groups of the given colIndexes.

Specified by:

getColGroupInfo in class AComEst

Parameters:

colIndexes - The columns to extract compression information from

estimate - An estimate of number of unique elements in these columns

nrUniqueUpperBound - The upper bound of unique elements allowed in the estimate, can be calculated from the number of unique elements estimated in sub columns multiplied together. This is flexible in the sense that if the sample is small then this unique can be manually edited like in CoCodeCostMatrixMult.

Returns:

The CompressedSizeInfoColGroup for the given column indexes.

getDeltaColGroupInfo

public CompressedSizeInfoColGroup getDeltaColGroupInfo(IColIndex colIndexes,
                                                       int estimate,
                                                       int nrUniqueUpperBound)

Description copied from class: AComEst

A method to extract the Compressed Size Info for a given list of columns, This method further limits the estimated number of unique values, since in some cases the estimated number of uniques is estimated higher than the number estimated in sub groups of the given colIndexes. The Difference for this method is that it extract the values as delta values from the matrix block input.

Specified by:

getDeltaColGroupInfo in class AComEst

Parameters:

colIndexes - The columns to extract compression information from

estimate - An estimate of number of unique delta elements in these columns

nrUniqueUpperBound - The upper bound of unique elements allowed in the estimate, can be calculated from the number of unique elements estimated in sub columns multiplied together. This is flexible in the sense that if the sample is small then this unique can be manually edited like in CoCodeCostMatrixMult.

Returns:

The CompressedSizeInfoColGroup for the given column indexes.