Package org.apache.orc.impl

Class SchemaEvolution

java.lang.Object

org.apache.orc.impl.SchemaEvolution

public class SchemaEvolution
extends Object

Infer and track the evolution between the schema as stored in the file and the schema that has been requested by the reader.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	SchemaEvolution.IllegalEvolutionException

Constructor Summary

Constructors

Constructor	Description
SchemaEvolution(TypeDescription fileSchema, boolean[] readerIncluded)	Deprecated.
SchemaEvolution(TypeDescription fileSchema, TypeDescription readerSchema, boolean[] readerIncluded)	Deprecated.
SchemaEvolution(TypeDescription fileSchema, TypeDescription readerSchema, Reader.Options options)

Method Summary

Modifier and Type	Method	Description
static boolean	checkAcidSchema(TypeDescription type)
static TypeDescription	createEventSchema(TypeDescription typeDescr)
static TypeDescription	getBaseRow(TypeDescription typeDescription)	Get the underlying base row from an ACID event struct.
boolean[]	getFileIncluded()	Get whether each column is included from the file's point of view.
TypeDescription	getFileSchema()
TypeDescription	getFileType(int id)	Get the file type by reader type id.
TypeDescription	getFileType(TypeDescription readerType)
boolean	getPositionalColumns()	Get whether the columns are handled via position or name
TypeDescription	getReaderBaseSchema()	Returns the non-ACID (aka base) reader type description.
boolean[]	getReaderIncluded()	Get whether each column is included from the reader's point of view.
TypeDescription	getReaderSchema()
boolean	hasConversion()	Is there Schema Evolution data type conversion?
boolean	includeReaderColumn(int readerId)	Should we read the given reader column?
boolean	isOnlyImplicitConversion()	When there Schema Evolution data type conversion i.e.
boolean	isPPDSafeConversion(int fileColId)	Check if column is safe for ppd evaluation
boolean	isSchemaEvolutionCaseAware()

Methods inherited from class java.lang.Object

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

Constructor Details

SchemaEvolution

public SchemaEvolution(TypeDescription fileSchema,
 TypeDescription readerSchema,
 Reader.Options options)

SchemaEvolution

@Deprecated
public SchemaEvolution(TypeDescription fileSchema,
 boolean[] readerIncluded)

Deprecated.

SchemaEvolution

@Deprecated
public SchemaEvolution(TypeDescription fileSchema,
 TypeDescription readerSchema,
 boolean[] readerIncluded)

Deprecated.

Method Details

isSchemaEvolutionCaseAware

public boolean isSchemaEvolutionCaseAware()

getReaderSchema

public TypeDescription getReaderSchema()

getReaderBaseSchema

public TypeDescription getReaderBaseSchema()

Returns the non-ACID (aka base) reader type description.

Returns:

the reader type ignoring the ACID rowid columns, if any

hasConversion

public boolean hasConversion()

Is there Schema Evolution data type conversion?

Returns:

isOnlyImplicitConversion

public boolean isOnlyImplicitConversion()

When there Schema Evolution data type conversion i.e. hasConversion() returns true, is the conversion only the implicit kind? (see aaa).

Returns:

getFileSchema

public TypeDescription getFileSchema()

getFileType

public TypeDescription getFileType(TypeDescription readerType)

getFileType

public TypeDescription getFileType(int id)

Get the file type by reader type id.

Parameters:

id - reader column id

Returns:

getReaderIncluded

public boolean[] getReaderIncluded()

Get whether each column is included from the reader's point of view.

Returns:

a boolean array indexed by reader column id

getFileIncluded

public boolean[] getFileIncluded()

Get whether each column is included from the file's point of view.

Returns:

a boolean array indexed by file column id

getPositionalColumns

public boolean getPositionalColumns()

Get whether the columns are handled via position or name

isPPDSafeConversion

public boolean isPPDSafeConversion(int fileColId)

Check if column is safe for ppd evaluation

Parameters:

fileColId - file column id

Returns:

true if the specified column is safe for ppd evaluation else false

includeReaderColumn

public boolean includeReaderColumn(int readerId)

Should we read the given reader column?

Parameters:

readerId - the id of column in the extended reader schema

Returns:

true if the column should be read

checkAcidSchema

public static boolean checkAcidSchema(TypeDescription type)

createEventSchema

public static TypeDescription createEventSchema(TypeDescription typeDescr)

Parameters:

typeDescr -

Returns:

ORC types for the ACID event based on the row's type description

getBaseRow

public static TypeDescription getBaseRow(TypeDescription typeDescription)

Get the underlying base row from an ACID event struct.

Parameters:

typeDescription - the ACID event schema.

Returns:

the subtype for the real row