Package org.apache.druid.query

Class DruidProcessingConfig

java.lang.Object

org.apache.druid.query.DruidProcessingConfig

All Implemented Interfaces:

ColumnConfig

public class DruidProcessingConfig
extends Object
implements ColumnConfig

Field Summary

Fields inherited from interface org.apache.druid.segment.column.ColumnConfig

DEFAULT, DEFAULT_SKIP_VALUE_RANGE_INDEX_SCALE, SELECTION_SIZE

Constructor Summary

Constructors

Constructor	Description
DruidProcessingConfig()
DruidProcessingConfig(String formatString, Integer numThreads, Integer numTimeoutThreads, Integer numMergeBuffers, Boolean fifo, String tmpDir, DruidProcessingBufferConfig buffer, DruidProcessingIndexesConfig indexes, RuntimeInfo runtimeInfo)

Method Summary

Modifier and Type	Method	Description
String	getFormatString()
int	getNumInitalBuffersForIntermediatePool()
int	getNumMergeBuffers()
int	getNumThreads()
int	getNumTimeoutThreads()
String	getTmpDir()
int	intermediateComputeSizeBytes()
boolean	isFifo()
boolean	isNumMergeBuffersConfigured()
boolean	isNumThreadsConfigured()
int	poolCacheMaxCount()
double	skipValueRangeIndexScale()	If the number of selected rows in a column multiplied by this value is smaller than the total number of bitmap index operations required to perform to use NumericRangeIndexes, then for any ColumnIndexSupplier which chooses to participate in this config it will skip computing the index, indicated by a return value of null from the 'forRange' methods, to force the filter to be processed with a scan using a ValueMatcher instead.

Methods inherited from class java.lang.Object

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

Constructor Details

DruidProcessingConfig

public DruidProcessingConfig(@Nullable
 String formatString,
 @Nullable
 Integer numThreads,
 @Nullable
 Integer numTimeoutThreads,
 @Nullable
 Integer numMergeBuffers,
 @Nullable
 Boolean fifo,
 @Nullable
 String tmpDir,
 DruidProcessingBufferConfig buffer,
 DruidProcessingIndexesConfig indexes,
 RuntimeInfo runtimeInfo)

DruidProcessingConfig

public DruidProcessingConfig()

Method Details

getFormatString

public String getFormatString()

getNumThreads

public int getNumThreads()

getNumTimeoutThreads

public int getNumTimeoutThreads()

getNumMergeBuffers

public int getNumMergeBuffers()

isFifo

public boolean isFifo()

getTmpDir

public String getTmpDir()

intermediateComputeSizeBytes

public int intermediateComputeSizeBytes()

poolCacheMaxCount

public int poolCacheMaxCount()

getNumInitalBuffersForIntermediatePool

public int getNumInitalBuffersForIntermediatePool()

skipValueRangeIndexScale

public double skipValueRangeIndexScale()

Description copied from interface: ColumnConfig

If the number of selected rows in a column multiplied by this value is smaller than the total number of bitmap index operations required to perform to use NumericRangeIndexes, then for any ColumnIndexSupplier which chooses to participate in this config it will skip computing the index, indicated by a return value of null from the 'forRange' methods, to force the filter to be processed with a scan using a ValueMatcher instead.

For range indexes on columns where every value has an index, the number of bitmap operations is determined by how many individual values fall in the range, a subset of the columns total cardinality.

Currently only the NestedCommonFormatColumn implementations of ColumnIndexSupplier support this behavior.

This can make some standalone filters faster in cases where the overhead of walking the value dictionary and combining bitmaps to construct a BitmapOffset or BitmapVectorOffset can exceed the cost of just using doing a full scan and using a ValueMatcher.

Where this is especially useful is in cases where the range index is used as part of some AndFilter, which segment processing partitions into groups of 'pre' filters, composed of those which should use indexes, and 'post' filters, which should use a matcher on the offset created by the indexes to filter the remaining results. This value pushes what would have been expensive index computations to go into the 'pre' group into using a value matcher as part of the 'post' group instead, sometimes providing an order of magnitude or higher performance increase.

Specified by:

skipValueRangeIndexScale in interface ColumnConfig

isNumThreadsConfigured

public boolean isNumThreadsConfigured()

isNumMergeBuffersConfigured

public boolean isNumMergeBuffersConfigured()