io.druid.segment

Interface ColumnSelectorFactory

All Known Subinterfaces:

Cursor

All Known Implementing Classes:

RowBasedColumnSelectorFactory, VirtualizedColumnSelectorFactory

public interface ColumnSelectorFactory

Factory class for MetricSelectors

Method Summary

Modifier and Type	Method and Description
ColumnCapabilities	getColumnCapabilities(String column) Returns capabilities of a particular column, if known.
DimensionSelector	makeDimensionSelector(DimensionSpec dimensionSpec)
FloatColumnSelector	makeFloatColumnSelector(String columnName)
LongColumnSelector	makeLongColumnSelector(String columnName)
ObjectColumnSelector	makeObjectColumnSelector(String columnName)

Method Detail

makeDimensionSelector

DimensionSelector makeDimensionSelector(DimensionSpec dimensionSpec)

makeFloatColumnSelector

FloatColumnSelector makeFloatColumnSelector(String columnName)

makeLongColumnSelector

LongColumnSelector makeLongColumnSelector(String columnName)

makeObjectColumnSelector

@Nullable
ObjectColumnSelector makeObjectColumnSelector(String columnName)

getColumnCapabilities

@Nullable
ColumnCapabilities getColumnCapabilities(String column)

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.

Parameters:

column - column name

Returns:

capabilities, or null