io.druid.segment

Interface ColumnSelectorFactory

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.
ColumnValueSelector	makeColumnValueSelector(String columnName) Returns ColumnValueSelector corresponding to the given column name, or NilColumnValueSelector if the column with such name is absent.
DimensionSelector	makeDimensionSelector(DimensionSpec dimensionSpec)

Method Detail

makeDimensionSelector

DimensionSelector makeDimensionSelector(DimensionSpec dimensionSpec)

makeColumnValueSelector

ColumnValueSelector makeColumnValueSelector(String columnName)

Returns ColumnValueSelector corresponding to the given column name, or NilColumnValueSelector if the column with such name is absent.

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