Package io.delta.kernel.internal.columndefaults

Class ColumnDefaults

Object

io.delta.kernel.internal.columndefaults.ColumnDefaults

public class ColumnDefaults
extends Object

Utilities class for TableFeature "allowColumnDefaults". NOTE: As of Aug 2025, kernel only supports reading Delta tables with the table feature, or modifying table metadata. Writing actual data to the table is not allowed.

Constructor Summary

Constructors

Constructor	Description
ColumnDefaults()

Method Summary

Modifier and Type	Method	Description
static void	blockWriteIfEnabled(Row transactionState)	Don't allow data writes to tables with default values
static String	getRawDefaultValue(StructField field)
static void	validateSchema(StructType schema, boolean isEnabled, boolean isIcebergCompatV3Enabled)	Validate Column Default values in the provided metadata.
static void	validateSchemaForIcebergCompat(StructType schema, String compatVersion)	Validate that the schema only contains literal default values as a requirement of IcebergCompat.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

ColumnDefaults

public ColumnDefaults()

Method Details

blockWriteIfEnabled

public static void blockWriteIfEnabled(Row transactionState)

Don't allow data writes to tables with default values

validateSchema

public static void validateSchema(StructType schema,
 boolean isEnabled,
 boolean isIcebergCompatV3Enabled)

Validate Column Default values in the provided metadata. Kernel only supports literal default values. See {validateLiteral}.

Parameters:

schema - target table schema

isEnabled - When the feature is disabled, no column default is allowed.

isIcebergCompatV3Enabled - Kernel currently requires IcebergCompatV3 to be enabled when using Column Defaults

Throws:

KernelException - when the table contains invalid default value

validateSchemaForIcebergCompat

public static void validateSchemaForIcebergCompat(StructType schema,
 String compatVersion)

Validate that the schema only contains literal default values as a requirement of IcebergCompat.

Parameters:

schema - table schema

getRawDefaultValue

public static String getRawDefaultValue(StructField field)