org.apache.paimon.flink

Class Projection

java.lang.Object

org.apache.paimon.flink.Projection

public abstract class Projection
extends Object

Projection represents a list of (possibly nested) indexes that can be used to project data types. A row projection includes both reducing the accessible fields and reordering them.

Method Summary

Modifier and Type	Method and Description
static Projection	empty() Create an empty Projection, that is a projection that projects no fields, returning an empty DataType.
boolean	equals(Object o)
int	hashCode()
abstract boolean	isNested()
static Projection	of(int[] indexes) Create a Projection of the provided indexes.
static Projection	of(int[][] indexes) Create a Projection of the provided indexes.
abstract org.apache.flink.table.types.logical.RowType	project(org.apache.flink.table.types.logical.RowType logicalType)
abstract int[][]	toNestedIndexes() Convert this instance to a nested projection index paths.
String	toString()
abstract int[]	toTopLevelIndexes() Convert this instance to a projection of top level indexes.

Methods inherited from class java.lang.Object

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

Method Detail

project

public abstract org.apache.flink.table.types.logical.RowType project(org.apache.flink.table.types.logical.RowType logicalType)

isNested

public abstract boolean isNested()

Returns:

true whether this projection is nested or not.

toTopLevelIndexes

public abstract int[] toTopLevelIndexes()

Convert this instance to a projection of top level indexes. The array represents the mapping of the fields of the original DataType. For example, [0, 2, 1] specifies to include in the following order the 1st field, the 3rd field and the 2nd field of the row.

Throws:

IllegalStateException - if this projection is nested.

toNestedIndexes

public abstract int[][] toNestedIndexes()

Convert this instance to a nested projection index paths. The array represents the mapping of the fields of the original DataType, including nested rows. For example, [[0, 2, 1], ...] specifies to include the 2nd field of the 3rd field of the 1st field in the top-level row.

empty

public static Projection empty()

Create an empty Projection, that is a projection that projects no fields, returning an empty DataType.

of

public static Projection of(int[] indexes)

Create a Projection of the provided indexes.

See Also:

toTopLevelIndexes()

of

public static Projection of(int[][] indexes)

Create a Projection of the provided indexes.

See Also:

toNestedIndexes()

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