Package org.apache.druid.segment.column

Class RowSignature

java.lang.Object

org.apache.druid.segment.column.RowSignature

All Implemented Interfaces:

Expr.InputBindingInspector, ColumnInspector

public class RowSignature
extends Object
implements ColumnInspector

Type signature for a row in a Druid datasource or query result.

See Also:

which returns signatures for query results, which returns signatures for inline datasources

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	RowSignature.Builder
static class	RowSignature.Finalization

Method Summary

Modifier and Type	Method	Description
static RowSignature.Builder	builder()
RowSignature	buildSafeSignature(com.google.common.collect.ImmutableList<String> requestedColumnNames)	Builds a safe RowSignature.
boolean	contains(int columnNumber)
boolean	contains(String columnName)	Returns whether this signature contains a named column.
static RowSignature	empty()
boolean	equals(Object o)
ColumnCapabilities	getColumnCapabilities(String column)	Returns capabilities of a particular column.
String	getColumnName(int columnNumber)	Returns the name of the column at position columnNumber.
List<String>	getColumnNames()	Returns a list of column names in the order they appear in this signature.
Optional<ColumnType>	getColumnType(int columnNumber)	Returns the type of the column at position columnNumber, or empty if the type is unknown.
Optional<ColumnType>	getColumnType(String columnName)	Returns the type of the column named columnName, or empty if the type is unknown or the column does not exist.
List<ColumnType>	getColumnTypes()	Returns the column types in the order they are in.
int	hashCode()
int	indexOf(String columnName)	Returns the first position of columnName in this row signature, or -1 if it does not appear.
boolean	isNumeric(String columnName)	Returns true if the column is a numeric type (TypeSignature.isNumeric()), otherwise false if the column is not a numeric type or is not present in the row signature.
int	size()	Returns the number of columns in this signature.
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

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

getType

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

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

Method Detail

builder

public static RowSignature.Builder builder()

empty

public static RowSignature empty()

getColumnName

public String getColumnName(int columnNumber)

Returns the name of the column at position columnNumber.

Throws:

IndexOutOfBoundsException - if columnNumber is not within our row length

getColumnType

public Optional<ColumnType> getColumnType(String columnName)

Returns the type of the column named columnName, or empty if the type is unknown or the column does not exist.

getColumnType

public Optional<ColumnType> getColumnType(int columnNumber)

Returns the type of the column at position columnNumber, or empty if the type is unknown.

Throws:

IndexOutOfBoundsException - if columnNumber is not within our row length

isNumeric

public boolean isNumeric(String columnName)

Returns true if the column is a numeric type (TypeSignature.isNumeric()), otherwise false if the column is not a numeric type or is not present in the row signature.

getColumnNames

public List<String> getColumnNames()

Returns a list of column names in the order they appear in this signature.

size

public int size()

Returns the number of columns in this signature.

contains

public boolean contains(String columnName)

Returns whether this signature contains a named column.

contains

public boolean contains(int columnNumber)

indexOf

public int indexOf(String columnName)

Returns the first position of columnName in this row signature, or -1 if it does not appear. Note: the same column name may appear more than once in a signature; if it does, this method will return the first appearance.

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object

getColumnCapabilities

@Nullable
public ColumnCapabilities getColumnCapabilities(String column)

Description copied from interface: ColumnInspector

Returns capabilities of a particular column.

Specified by:

getColumnCapabilities in interface ColumnInspector

Parameters:

column - column name

Returns:

capabilities, or null

buildSafeSignature

public RowSignature buildSafeSignature(com.google.common.collect.ImmutableList<String> requestedColumnNames)

Builds a safe RowSignature. The new rowsignature will not contain `null` types - they will be replaced by STRING.

getColumnTypes

public List<ColumnType> getColumnTypes()

Returns the column types in the order they are in.