org.apache.flink.table.runtime.hashtable

Class BinaryHashTable

java.lang.Object

org.apache.flink.table.runtime.hashtable.BaseHybridHashTable

org.apache.flink.table.runtime.hashtable.BinaryHashTable

All Implemented Interfaces:

MemorySegmentSource, MemorySegmentPool

public class BinaryHashTable
extends BaseHybridHashTable

An implementation of a Hybrid Hash Join. The join starts operating in memory and gradually starts spilling contents to disk, when the memory is not sufficient. It does not need to know a priority how large the input will be.

The design of this class follows in many parts the design presented in "Hash joins and hash teams in Microsoft SQL Server", by Goetz Graefe et al. In its current state, the implementation lacks features like dynamic role reversal, partition tuning, or histogram guided partitioning.

Field Summary

Fields inherited from class org.apache.flink.table.runtime.hashtable.BaseHybridHashTable

buildRowCount, buildSpillRetBufferNumbers, buildSpillReturnBuffers, closed, compressionBlockSize, compressionCodecFactory, compressionEnable, currentEnumerator, currentRecursionDepth, currentSpilledBuildSide, currentSpilledProbeSide, initPartitionFanOut, internalPool, ioManager, LOG, MAX_NUM_PARTITIONS, MAX_RECURSION_DEPTH, numSpillFiles, segmentSize, segmentSizeBits, segmentSizeMask, spillInBytes, totalNumBuffers, tryDistinctBuildRow

Constructor Summary

Constructors

Constructor and Description

BinaryHashTable(Configuration conf, Object owner, AbstractRowDataSerializer buildSideSerializer, AbstractRowDataSerializer probeSideSerializer, Projection<RowData,BinaryRowData> buildSideProjection, Projection<RowData,BinaryRowData> probeSideProjection, MemoryManager memManager, long reservedMemorySize, IOManager ioManager, int avgRecordLen, long buildRowCount, boolean useBloomFilters, HashJoinType type, JoinCondition condFunc, boolean reverseJoin, boolean[] filterNulls, boolean tryDistinctBuildRow)

Method Summary

Modifier and Type	Method and Description
void	clearPartitions() This method clears all partitions currently residing (partially) in memory.
void	endBuild() End build phase.
RowIterator<BinaryRowData>	getBuildSideIterator()
RowData	getCurrentProbeRow()
boolean	nextMatching() Next record from rebuilt spilled partition or build side outer partition.
void	putBuildRow(RowData row) Put a build side row to hash table.
protected int	spillPartition() Selects a partition and spills it.
boolean	tryProbe(RowData record) Find matched build side rows for a probe row.

Methods inherited from class org.apache.flink.table.runtime.hashtable.BaseHybridHashTable

close, createInputView, ensureNumBuffersReturned, free, freeCurrent, freePages, getNextBuffer, getNextBuffers, getNotNullNextBuffer, getNumSpillFiles, getSpillInBytes, getUsedMemoryInBytes, hash, maxInitBufferOfBucketArea, maxNumPartition, nextSegment, pageSize, readAllBuffers, remainBuffers, returnAll, returnPage

Methods inherited from class java.lang.Object

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

Constructor Detail

BinaryHashTable

public BinaryHashTable(Configuration conf,
                       Object owner,
                       AbstractRowDataSerializer buildSideSerializer,
                       AbstractRowDataSerializer probeSideSerializer,
                       Projection<RowData,BinaryRowData> buildSideProjection,
                       Projection<RowData,BinaryRowData> probeSideProjection,
                       MemoryManager memManager,
                       long reservedMemorySize,
                       IOManager ioManager,
                       int avgRecordLen,
                       long buildRowCount,
                       boolean useBloomFilters,
                       HashJoinType type,
                       JoinCondition condFunc,
                       boolean reverseJoin,
                       boolean[] filterNulls,
                       boolean tryDistinctBuildRow)

Method Detail

putBuildRow

public void putBuildRow(RowData row)
                 throws IOException

Put a build side row to hash table.

Throws:

IOException

endBuild

public void endBuild()
              throws IOException

End build phase.

Throws:

IOException

tryProbe

public boolean tryProbe(RowData record)
                 throws IOException

Find matched build side rows for a probe row.

Returns:

return false if the target partition has spilled, we will spill this probe row too. The row will be re-match in rebuild phase.

Throws:

IOException

nextMatching

public boolean nextMatching()
                     throws IOException

Next record from rebuilt spilled partition or build side outer partition.

Throws:

IOException

getCurrentProbeRow

public RowData getCurrentProbeRow()

getBuildSideIterator

public RowIterator<BinaryRowData> getBuildSideIterator()

clearPartitions

public void clearPartitions()

This method clears all partitions currently residing (partially) in memory. It releases all memory and deletes all spilled partitions.

This method is intended for a hard cleanup in the case that the join is aborted.

Specified by:

clearPartitions in class BaseHybridHashTable

spillPartition

protected int spillPartition()
                      throws IOException

Selects a partition and spills it. The number of the spilled partition is returned.

Specified by:

spillPartition in class BaseHybridHashTable

Returns:

The number of the spilled partition.

Throws:

IOException