io.delta.kernel.internal.util

Class ColumnMapping

Object

io.delta.kernel.internal.util.ColumnMapping

public class ColumnMapping
extends Object

Utilities related to the column mapping feature.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ColumnMapping.ColumnMappingMode

Field Summary

Fields

Modifier and Type	Field and Description
static String	COLUMN_MAPPING_ID_KEY
static String	COLUMN_MAPPING_MAX_COLUMN_ID_KEY
static String	COLUMN_MAPPING_MODE_KEY
static String	COLUMN_MAPPING_NESTED_IDS_KEY
static String	COLUMN_MAPPING_PHYSICAL_NAME_KEY
static String	PARQUET_FIELD_ID_KEY
static String	PARQUET_FIELD_NESTED_IDS_METADATA_KEY

Method Summary

Modifier and Type	Method and Description
static StructType	convertToPhysicalSchema(StructType logicalSchema, StructType physicalSchema, ColumnMapping.ColumnMappingMode columnMappingMode) Helper method that converts the logical schema (requested by the connector) to physical schema of the data stored in data files based on the table's column mapping mode.
static ColumnMapping.ColumnMappingMode	getColumnMappingMode(java.util.Map<String,String> configuration) Returns the column mapping mode from the given configuration.
static String	getPhysicalName(StructField field) Returns the physical name for a given StructField
static boolean	isColumnMappingModeEnabled(ColumnMapping.ColumnMappingMode columnMappingMode)
static void	throwOnUnsupportedColumnMappingMode(Metadata metadata) Checks if the given column mapping mode in the given table metadata is supported.
static Metadata	updateColumnMappingMetadata(Metadata metadata, ColumnMapping.ColumnMappingMode columnMappingMode, boolean isNewTable)
static void	verifyColumnMappingChange(java.util.Map<String,String> oldConfig, java.util.Map<String,String> newConfig, boolean isNewTable)

Methods inherited from class Object

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

Field Detail

COLUMN_MAPPING_MODE_KEY

public static final String COLUMN_MAPPING_MODE_KEY

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Constant Field Values

COLUMN_MAPPING_PHYSICAL_NAME_KEY

public static final String COLUMN_MAPPING_PHYSICAL_NAME_KEY

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Constant Field Values

COLUMN_MAPPING_ID_KEY

public static final String COLUMN_MAPPING_ID_KEY

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Constant Field Values

COLUMN_MAPPING_NESTED_IDS_KEY

public static final String COLUMN_MAPPING_NESTED_IDS_KEY

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Constant Field Values

PARQUET_FIELD_ID_KEY

public static final String PARQUET_FIELD_ID_KEY

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Constant Field Values

PARQUET_FIELD_NESTED_IDS_METADATA_KEY

public static final String PARQUET_FIELD_NESTED_IDS_METADATA_KEY

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Constant Field Values

COLUMN_MAPPING_MAX_COLUMN_ID_KEY

public static final String COLUMN_MAPPING_MAX_COLUMN_ID_KEY

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Constant Field Values

Method Detail

getColumnMappingMode

public static ColumnMapping.ColumnMappingMode getColumnMappingMode(java.util.Map<String,String> configuration)

Returns the column mapping mode from the given configuration.

Parameters:

configuration - Configuration

Returns:

Column mapping mode. One of ("none", "name", "id")

throwOnUnsupportedColumnMappingMode

public static void throwOnUnsupportedColumnMappingMode(Metadata metadata)

Checks if the given column mapping mode in the given table metadata is supported. Throws on unsupported modes.

Parameters:

metadata - Metadata of the table

convertToPhysicalSchema

public static StructType convertToPhysicalSchema(StructType logicalSchema,
                                                 StructType physicalSchema,
                                                 ColumnMapping.ColumnMappingMode columnMappingMode)

Helper method that converts the logical schema (requested by the connector) to physical schema of the data stored in data files based on the table's column mapping mode.

Parameters:

logicalSchema - Logical schema of the scan

physicalSchema - Physical schema of the scan

columnMappingMode - Column mapping mode

getPhysicalName

public static String getPhysicalName(StructField field)

Returns the physical name for a given StructField

verifyColumnMappingChange

public static void verifyColumnMappingChange(java.util.Map<String,String> oldConfig,
                                             java.util.Map<String,String> newConfig,
                                             boolean isNewTable)

isColumnMappingModeEnabled

public static boolean isColumnMappingModeEnabled(ColumnMapping.ColumnMappingMode columnMappingMode)

updateColumnMappingMetadata

public static Metadata updateColumnMappingMetadata(Metadata metadata,
                                                   ColumnMapping.ColumnMappingMode columnMappingMode,
                                                   boolean isNewTable)