Package org.apache.druid.segment

Class ColumnCache

java.lang.Object

org.apache.druid.segment.ColumnCache

All Implemented Interfaces:

Expr.InputBindingInspector, ColumnIndexSelector, ColumnInspector, ColumnSelector

public class ColumnCache
extends Object
implements ColumnIndexSelector

Wraps QueryableIndex and VirtualColumns, providing a unified view of physical and virtual columns, as well as lifecycle management for physical columns.

Constructor Summary

Constructors

Constructor	Description
ColumnCache(QueryableIndex index, VirtualColumns virtualColumns, Closer closer)

Method Summary

Modifier and Type	Method	Description
BitmapFactory	getBitmapFactory()
ColumnHolder	getColumnHolder(String columnName)
ColumnIndexSupplier	getIndexSupplier(String column)	Get the ColumnIndexSupplier of a column.
int	getNumRows()

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

getType

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

getColumnCapabilities

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

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

Constructor Details

ColumnCache

public ColumnCache(QueryableIndex index,
 VirtualColumns virtualColumns,
 Closer closer)

Method Details

getColumnHolder

@Nullable
public ColumnHolder getColumnHolder(String columnName)

Specified by:

getColumnHolder in interface ColumnSelector

getNumRows

public int getNumRows()

Specified by:

getNumRows in interface ColumnIndexSelector

getBitmapFactory

public BitmapFactory getBitmapFactory()

Specified by:

getBitmapFactory in interface ColumnIndexSelector

getIndexSupplier

@Nullable
public ColumnIndexSupplier getIndexSupplier(String column)

Description copied from interface: ColumnIndexSelector

Get the ColumnIndexSupplier of a column. If the column exists, but does not support indexes, this method will return a non-null index supplier, likely NoIndexesColumnIndexSupplier. Columns which are 'missing' will return a null value from this method, which allows for filters to act on this information to produce an all true or all false index depending on how the filter matches the null value.

Specified by:

getIndexSupplier in interface ColumnIndexSelector