Package org.apache.druid.segment.index

Class DictionaryRangeScanningBitmapIndex

java.lang.Object

org.apache.druid.segment.index.SimpleBitmapColumnIndex

org.apache.druid.segment.index.SimpleImmutableBitmapDelegatingIterableIndex

org.apache.druid.segment.index.DictionaryRangeScanningBitmapIndex

All Implemented Interfaces:

BitmapColumnIndex

public abstract class DictionaryRangeScanningBitmapIndex
extends SimpleImmutableBitmapDelegatingIterableIndex

Common BitmapColumnIndex implementation for indexes which need to scan a range of values. Contains logic to skip computing indexes with computeBitmapResult(BitmapResultFactory, int, int, boolean) if rangeSize is larger than sizeScale multiplied by the number of selected rows. Numeric range indexes will typically want to set sizeScale to a double closer to 0.0 than to 1.0 because numeric comparisons are relatively cheap compared to bitmap operations. Most numerical implementations should use the value of ColumnConfig.skipValueRangeIndexScale().

Other implementations should adjust sizeScale as appropriate for the expense of the value matcher compared to the expense of the bitmap operations.

Field Summary

Fields inherited from class org.apache.druid.segment.index.SimpleBitmapColumnIndex

CAPABILITIES

Constructor Summary

Constructors

Constructor	Description
DictionaryRangeScanningBitmapIndex(double sizeScale, int rangeSize)

Method Summary

Modifier and Type	Method	Description
<T> T	computeBitmapResult(BitmapResultFactory<T> bitmapResultFactory, int applyRowCount, int totalRowCount, boolean includeUnknown)	Compute a bitmap result wrapped with the BitmapResultFactory representing the rows matched by this index, or null if the index cannot (or should not) be computed.

Methods inherited from class org.apache.druid.segment.index.SimpleImmutableBitmapDelegatingIterableIndex

computeBitmapResult, getBitmapIterable, getUnknownsBitmap

Methods inherited from class org.apache.druid.segment.index.SimpleBitmapColumnIndex

getIndexCapabilities

Methods inherited from class java.lang.Object

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

Constructor Detail

DictionaryRangeScanningBitmapIndex

public DictionaryRangeScanningBitmapIndex(double sizeScale,
                                          int rangeSize)

Method Detail

computeBitmapResult

@Nullable
public final <T> T computeBitmapResult(BitmapResultFactory<T> bitmapResultFactory,
                                       int applyRowCount,
                                       int totalRowCount,
                                       boolean includeUnknown)

Description copied from interface: BitmapColumnIndex

Compute a bitmap result wrapped with the BitmapResultFactory representing the rows matched by this index, or null if the index cannot (or should not) be computed.

Parameters:

bitmapResultFactory - helper to format the ImmutableBitmap in a form ready for consumption by callers

applyRowCount - upper bound on number of rows this filter would be applied to, after removing rows short-circuited by prior bundle operations. For example, given "x AND y", if "x" is resolved using an index, then "y" will receive the number of rows that matched the filter "x". As another example, given "x OR y", if "x" is resolved using an index, then "y" will receive the number of rows that did *not* match the filter "x".

totalRowCount - total number of rows to be scanned if no indexes are used

includeUnknown - mapping for Druid native two state logic system into SQL three-state logic system. If set to true, bitmaps returned by this method should include true bits for any rows where the matching result is 'unknown', such as from the input being null valued. See NullHandling.useThreeValueLogic().

Returns:

bitmap result representing rows matched by this index