Package org.apache.beam.sdk.io.iceberg

Enum Class SchemaEvolutionOption

java.lang.Object

java.lang.Enum<SchemaEvolutionOption>

org.apache.beam.sdk.io.iceberg.SchemaEvolutionOption

All Implemented Interfaces:

Serializable, Comparable<SchemaEvolutionOption>, Constable

public enum SchemaEvolutionOption
extends Enum<SchemaEvolutionOption>

Kinds of table schema change AddFiles may make so that a file's columns are covered by the table schema. Evolution is all or nothing per file schema: a file schema needing a change that is not allowed is incompatible; see SchemaEvolutionConfig.IncompatibleSchemaHandling for what happens to its files. Pinned columns (SchemaEvolutionConfig.getRequiredColumns()) are never relaxed whatever the options.

The options constrain changes to columns the table already has when a window's schema commit starts (the whole input, in batch). A column that is new in that window takes the union of the window's file schemas: its type is the widest among them and it is optional (a pinned column is created required only when the transform creates the table), so two files that disagree about a new column never conflict with each other, only with the table.

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Enum

Enum.EnumDesc<E extends Enum<E>>

Enum Constant Summary

Enum Constants

Enum Constant	Description
ALLOW_FIELD_ADDITION	Add columns present in files but absent from the table, as optional columns at every level (a pinned column is created required).
ALLOW_FIELD_RELAXATION	Make a required table column optional when a file has nulls in it, carries no null-count statistics for it, or lacks it entirely (every row would read null).
ALLOW_TYPE_PROMOTION	Widen a column's type (int to long, float to double, decimal precision) when a file needs it.

Method Summary

Modifier and Type	Method	Description
static SchemaEvolutionOption	valueOf(String name)	Returns the enum constant of this class with the specified name.
static SchemaEvolutionOption[]	values()	Returns an array containing the constants of this enum class, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, describeConstable, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Details

ALLOW_FIELD_ADDITION

public static final SchemaEvolutionOption ALLOW_FIELD_ADDITION

Add columns present in files but absent from the table, as optional columns at every level (a pinned column is created required). Also lets this transform create a missing table from the union of the file schemas.

ALLOW_FIELD_RELAXATION

public static final SchemaEvolutionOption ALLOW_FIELD_RELAXATION

Make a required table column optional when a file has nulls in it, carries no null-count statistics for it, or lacks it entirely (every row would read null). For a column outside lists and maps, a file whose footer proves zero nulls never triggers this, however its writer declared the column; under a list or map the declaration is taken as is. Relaxation is table-wide and permanent; pin the columns that must stay required.

ALLOW_TYPE_PROMOTION

public static final SchemaEvolutionOption ALLOW_TYPE_PROMOTION

Widen a column's type (int to long, float to double, decimal precision) when a file needs it.

Method Details

values

public static SchemaEvolutionOption[] values()

Returns an array containing the constants of this enum class, in the order they are declared.

Returns:

an array containing the constants of this enum class, in the order they are declared

valueOf

public static SchemaEvolutionOption valueOf(String name)

Returns the enum constant of this class with the specified name. The string must match exactly an identifier used to declare an enum constant in this class. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum class has no constant with the specified name

NullPointerException - if the argument is null