Package org.apache.druid.segment

Class UnnestStorageAdapter

java.lang.Object

org.apache.druid.segment.UnnestStorageAdapter

All Implemented Interfaces:

Expr.InputBindingInspector, ColumnInspector, CursorFactory, StorageAdapter

public class UnnestStorageAdapter
extends Object
implements StorageAdapter

This class serves as the Storage Adapter for the Unnest Segment and is responsible for creating the cursors If the column is dictionary encoded it creates UnnestDimensionCursor else UnnestColumnValueSelectorCursor These cursors help navigate the segments for these cases

Constructor Summary

Constructors

Constructor	Description
UnnestStorageAdapter(StorageAdapter baseAdapter, VirtualColumn unnestColumn, DimFilter unnestFilter)

Method Summary

Modifier and Type	Method	Description
Pair<Filter,Filter>	computeBaseAndPostUnnestFilters(Filter queryFilter, Filter unnestFilter, VirtualColumns queryVirtualColumns, String inputColumn, ColumnCapabilities inputColumnCapabilites)	Split queryFilter into pre- and post-correlate filters.
Indexed<String>	getAvailableDimensions()
Iterable<String>	getAvailableMetrics()
StorageAdapter	getBaseAdapter()
ColumnCapabilities	getColumnCapabilities(String column)	Returns capabilities of a particular column, if known.
int	getDimensionCardinality(String column)	Returns the number of distinct values for a column, or DimensionDictionarySelector.CARDINALITY_UNKNOWN if unknown.
org.joda.time.Interval	getInterval()
org.joda.time.DateTime	getMaxIngestedEventTime()
org.joda.time.DateTime	getMaxTime()	Metadata-only operation that returns an upper bound on ColumnHolder.TIME_COLUMN_NAME values for this adapter.
Comparable	getMaxValue(String column)	Returns the minimum value of the provided column, if known through an index, dictionary, or cache.
Metadata	getMetadata()
org.joda.time.DateTime	getMinTime()	Metadata-only operation that returns a lower bound on ColumnHolder.TIME_COLUMN_NAME values for this adapter.
Comparable	getMinValue(String column)	Returns the minimum value of the provided column, if known through an index, dictionary, or cache.
int	getNumRows()
VirtualColumn	getUnnestColumn()
Filter	getUnnestFilter()
String	getUnnestInputIfDirectAccess(VirtualColumn unnestColumn)	Returns the input of unnestColumn, if it's a direct access; otherwise returns null.
Sequence<Cursor>	makeCursors(Filter filter, org.joda.time.Interval interval, VirtualColumns virtualColumns, Granularity gran, boolean descending, QueryMetrics<?> queryMetrics)	Creates a sequence of Cursors, one for each time-granular bucket (based on the provided Granularity).

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.druid.segment.ColumnInspector

getColumnCapabilitiesWithDefault, getType

Methods inherited from interface org.apache.druid.segment.CursorFactory

canVectorize, makeVectorCursor

Methods inherited from interface org.apache.druid.math.expr.Expr.InputBindingInspector

areNumeric, areNumeric, areSameTypes, areSameTypes, areScalar, areScalar, canVectorize, canVectorize

Methods inherited from interface org.apache.druid.segment.StorageAdapter

getRowSignature, hasBuiltInFilters, isFromTombstone

Constructor Detail

UnnestStorageAdapter

public UnnestStorageAdapter(StorageAdapter baseAdapter,
                            VirtualColumn unnestColumn,
                            @Nullable
                            DimFilter unnestFilter)

Method Detail

getBaseAdapter

public StorageAdapter getBaseAdapter()

makeCursors

public Sequence<Cursor> makeCursors(@Nullable
                                    Filter filter,
                                    org.joda.time.Interval interval,
                                    VirtualColumns virtualColumns,
                                    Granularity gran,
                                    boolean descending,
                                    @Nullable
                                    QueryMetrics<?> queryMetrics)

Description copied from interface: CursorFactory

Creates a sequence of Cursors, one for each time-granular bucket (based on the provided Granularity).

Specified by:

makeCursors in interface CursorFactory

getInterval

public org.joda.time.Interval getInterval()

Specified by:

getInterval in interface StorageAdapter

getAvailableDimensions

public Indexed<String> getAvailableDimensions()

Specified by:

getAvailableDimensions in interface StorageAdapter

getAvailableMetrics

public Iterable<String> getAvailableMetrics()

Specified by:

getAvailableMetrics in interface StorageAdapter

getUnnestFilter

@Nullable
public Filter getUnnestFilter()

getDimensionCardinality

public int getDimensionCardinality(String column)

Description copied from interface: StorageAdapter

Returns the number of distinct values for a column, or DimensionDictionarySelector.CARDINALITY_UNKNOWN if unknown. If the column doesn't exist, returns 1, because a column that doesn't exist is treated as a column of default (or null) values.

Specified by:

getDimensionCardinality in interface StorageAdapter

getMinTime

public org.joda.time.DateTime getMinTime()

Description copied from interface: StorageAdapter

Metadata-only operation that returns a lower bound on ColumnHolder.TIME_COLUMN_NAME values for this adapter. May be earlier than the actual minimum data timestamp. For QueryableIndexStorageAdapter and IncrementalIndexStorageAdapter specifically, which back regular tables (i.e. TableDataSource), this method contract is tighter: it does return the actual minimum data timestamp. This fact is leveraged by TimeBoundaryQuery to return results using metadata only.

Specified by:

getMinTime in interface StorageAdapter

getMaxTime

public org.joda.time.DateTime getMaxTime()

Description copied from interface: StorageAdapter

Metadata-only operation that returns an upper bound on ColumnHolder.TIME_COLUMN_NAME values for this adapter. May be later than the actual maximum data timestamp. For QueryableIndexStorageAdapter and IncrementalIndexStorageAdapter specifically, which back regular tables (i.e. TableDataSource), this method contract is tighter: it does return the actual maximum data timestamp. This fact is leveraged by TimeBoundaryQuery to return results using metadata only.

Specified by:

getMaxTime in interface StorageAdapter

getMinValue

@Nullable
public Comparable getMinValue(String column)

Description copied from interface: StorageAdapter

Returns the minimum value of the provided column, if known through an index, dictionary, or cache. Returns null if not known. Does not scan the column to find the minimum value.

Specified by:

getMinValue in interface StorageAdapter

getMaxValue

@Nullable
public Comparable getMaxValue(String column)

Description copied from interface: StorageAdapter

Returns the minimum value of the provided column, if known through an index, dictionary, or cache. Returns null if not known. Does not scan the column to find the maximum value.

Specified by:

getMaxValue in interface StorageAdapter

getColumnCapabilities

@Nullable
public ColumnCapabilities getColumnCapabilities(String column)

Description copied from interface: StorageAdapter

Returns capabilities of a particular column, if known. May be null if the column doesn't exist, or if the column does exist but the capabilities are unknown. The latter is possible with dynamically discovered columns. Note that StorageAdapters are representations of "real" segments, so they are not aware of any virtual columns that may be involved in a query. In general, query engines should instead use the method ColumnSelectorFactory.getColumnCapabilities(String), which returns capabilities for virtual columns as well.

Specified by:

getColumnCapabilities in interface ColumnInspector

Specified by:

getColumnCapabilities in interface StorageAdapter

Parameters:

column - column name

Returns:

capabilities, or null

getNumRows

public int getNumRows()

Specified by:

getNumRows in interface StorageAdapter

getMaxIngestedEventTime

public org.joda.time.DateTime getMaxIngestedEventTime()

Specified by:

getMaxIngestedEventTime in interface StorageAdapter

getMetadata

@Nullable
public Metadata getMetadata()

Specified by:

getMetadata in interface StorageAdapter

getUnnestColumn

public VirtualColumn getUnnestColumn()

computeBaseAndPostUnnestFilters

public Pair<Filter,Filter> computeBaseAndPostUnnestFilters(@Nullable
                                                                 Filter queryFilter,
                                                                 @Nullable
                                                                 Filter unnestFilter,
                                                                 VirtualColumns queryVirtualColumns,
                                                                 @Nullable
                                                                 String inputColumn,
                                                                 @Nullable
                                                                 ColumnCapabilities inputColumnCapabilites)

Split queryFilter into pre- and post-correlate filters.

Parameters:

queryFilter - query filter passed to makeCursors

unnestFilter - filter on unnested column passed to PostUnnestCursor

queryVirtualColumns - query virtual columns passed to makeCursors

inputColumn - input column to unnest if it's a direct access; otherwise null

inputColumnCapabilites - input column capabilities if known; otherwise null

Returns:

pair of pre- and post-unnest filters

getUnnestInputIfDirectAccess

@Nullable
public String getUnnestInputIfDirectAccess(VirtualColumn unnestColumn)

Returns the input of unnestColumn, if it's a direct access; otherwise returns null.