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

Class AComEst

java.lang.Object

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

Direct Known Subclasses:

ComEstCompressed, ComEstExact, ComEstSample

public abstract class AComEst
extends Object

Main abstract class for estimating size of compressions on columns.

Method Summary

Modifier and Type	Method	Description
void	clearNNZ()	Clear the pointer to the materialized list of nnz in columns
CompressedSizeInfoColGroup	combine(IColIndex combinedColumns, CompressedSizeInfoColGroup g1, CompressedSizeInfoColGroup g2)	Combine two analyzed column groups together.
CompressedSizeInfoColGroup	combine(CompressedSizeInfoColGroup g1, CompressedSizeInfoColGroup g2)	combine two analyzed column groups together.
CompressedSizeInfo	computeCompressedSizeInfos(int k)	Multi threaded version of extracting compression size info
CompressedSizeInfoColGroup	getColGroupInfo(IColIndex colIndexes)	Method for extracting Compressed Size Info of specified columns, together in a single ColGroup
abstract 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)	Method for extracting info of specified columns as delta encodings (delta from previous rows values)
abstract 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.
String	toString()

Methods inherited from class java.lang.Object

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

Method Detail

computeCompressedSizeInfos

public final CompressedSizeInfo computeCompressedSizeInfos(int k)

Multi threaded version of extracting compression size info

Parameters:

k - The concurrency degree.

Returns:

The Compression Size info of each Column compressed isolated.

getColGroupInfo

public final CompressedSizeInfoColGroup getColGroupInfo(IColIndex colIndexes)

Method for extracting Compressed Size Info of specified columns, together in a single ColGroup

Parameters:

colIndexes - The columns to group together inside a ColGroup

Returns:

The CompressedSizeInformation associated with the selected ColGroups.

getColGroupInfo

public abstract 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.

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 final CompressedSizeInfoColGroup getDeltaColGroupInfo(IColIndex colIndexes)

Method for extracting info of specified columns as delta encodings (delta from previous rows values)

Parameters:

colIndexes - The columns to group together inside a ColGroup

Returns:

The CompressedSizeInformation assuming delta encoding of the column.

getDeltaColGroupInfo

public abstract 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. The Difference for this method is that it extract the values as delta values from the matrix block input.

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.

combine

public final CompressedSizeInfoColGroup combine(CompressedSizeInfoColGroup g1,
                                                CompressedSizeInfoColGroup g2)

combine two analyzed column groups together. without materializing the dictionaries of either side. if the number of distinct elements in both sides multiplied is larger than Integer, return null. If either side was constructed without analysis then fall back to default materialization of double arrays. O

Parameters:

g1 - First group

g2 - Second group

Returns:

A combined compressed size estimation for the group.

combine

public final CompressedSizeInfoColGroup combine(IColIndex combinedColumns,
                                                CompressedSizeInfoColGroup g1,
                                                CompressedSizeInfoColGroup g2)

Combine two analyzed column groups together. without materializing the dictionaries of either side. if the number of distinct elements in both sides multiplied is larger than Integer, return null. If either side was constructed without analysis then fall back to default materialization of double arrays.

Parameters:

combinedColumns - The combined column indexes.

g1 - First group

g2 - Second group

Returns:

A combined compressed size estimation for the columns specified using the combining algorithm

clearNNZ

public void clearNNZ()

Clear the pointer to the materialized list of nnz in columns

toString

public String toString()

Overrides:

toString in class Object