org.apache.hadoop.hive.serde2.columnar
Class ColumnarSerDe

java.lang.Object
  org.apache.hadoop.hive.serde2.columnar.ColumnarSerDe

All Implemented Interfaces:

Deserializer, SerDe, Serializer

public class ColumnarSerDe
extends Object
implements SerDe

ColumnarSerDe is used for columnar based storage supported by RCFile. ColumnarSerDe differentiate from LazySimpleSerDe in:
(1) ColumnarSerDe uses a ColumnarStruct as its lazy Object
(2) ColumnarSerDe initialize ColumnarStruct's field directly. But under the field level, it works like LazySimpleSerDe

Field Summary

static org.apache.commons.logging.Log

LOG

Constructor Summary

ColumnarSerDe()

Method Summary

Object	deserialize(org.apache.hadoop.io.Writable blob) Deserialize a row from the Writable to a LazyObject.
ObjectInspector	getObjectInspector() Returns the ObjectInspector for the row.
Class<? extends org.apache.hadoop.io.Writable>	getSerializedClass() Returns the Writable Class after serialization.
void	initialize(org.apache.hadoop.conf.Configuration job, Properties tbl) Initialize the SerDe given the parameters.
org.apache.hadoop.io.Writable	serialize(Object obj, ObjectInspector objInspector) Serialize a row of data.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

LOG

public static final org.apache.commons.logging.Log LOG

Constructor Detail

ColumnarSerDe

public ColumnarSerDe()
              throws SerDeException

Throws:

SerDeException

Method Detail

toString

public String toString()

Overrides:

toString in class Object

initialize

public void initialize(org.apache.hadoop.conf.Configuration job,
                       Properties tbl)
                throws SerDeException

Initialize the SerDe given the parameters.

Specified by:

initialize in interface Deserializer

Specified by:

initialize in interface Serializer

Parameters:

job - System properties

tbl - table properties

Throws:

SerDeException

See Also:

Deserializer.initialize(Configuration, Properties)

deserialize

public Object deserialize(org.apache.hadoop.io.Writable blob)
                   throws SerDeException

Deserialize a row from the Writable to a LazyObject.

Specified by:

deserialize in interface Deserializer

Parameters:

blob - The Writable object containing a serialized object

Returns:

A Java object representing the contents in the blob.

Throws:

SerDeException

getObjectInspector

public ObjectInspector getObjectInspector()
                                   throws SerDeException

Returns the ObjectInspector for the row.

Specified by:

getObjectInspector in interface Deserializer

Throws:

SerDeException

getSerializedClass

public Class<? extends org.apache.hadoop.io.Writable> getSerializedClass()

Returns the Writable Class after serialization.

Specified by:

getSerializedClass in interface Serializer

See Also:

Serializer.getSerializedClass()

serialize

public org.apache.hadoop.io.Writable serialize(Object obj,
                                               ObjectInspector objInspector)
                                        throws SerDeException

Serialize a row of data.

Specified by:

serialize in interface Serializer

Parameters:

obj - The row object

objInspector - The ObjectInspector for the row object

Returns:

The serialized Writable object

Throws:

SerDeException

See Also:

Serializer.serialize(Object, ObjectInspector)