org.apache.hadoop.hive.ql.io.arrow

Class ArrowColumnarBatchSerDe

java.lang.Object

org.apache.hadoop.hive.serde2.AbstractSerDe

org.apache.hadoop.hive.ql.io.arrow.ArrowColumnarBatchSerDe

All Implemented Interfaces:

Deserializer, Serializer

public class ArrowColumnarBatchSerDe
extends AbstractSerDe

ArrowColumnarBatchSerDe converts Apache Hive rows to Apache Arrow columns. Its serialized class is ArrowWrapperWritable, which doesn't support Writable.readFields(DataInput) and Writable.write(DataOutput). Followings are known issues of current implementation. A list column cannot have a decimal column. UnionListWriter doesn't have an implementation for BaseWriter.ListWriter#decimal(). A union column can have only one of string, char, varchar fields at a same time. Apache Arrow doesn't have string and char, so ArrowColumnarBatchSerDe uses varchar to simulate string and char. They will be considered as a same data type in UnionVector. Timestamp with local timezone is not supported. VectorAssignRow doesn't support it.

Field Summary

Fields

Modifier and Type	Field and Description
static org.slf4j.Logger	LOG

Fields inherited from class org.apache.hadoop.hive.serde2.AbstractSerDe

configErrors

Constructor Summary

Constructors

Constructor and Description
ArrowColumnarBatchSerDe()

Method Summary

Modifier and Type	Method and Description
Object	deserialize(org.apache.hadoop.io.Writable writable) Deserialize an object out of a Writable blob.
ObjectInspector	getObjectInspector() Get the object inspector that can be used to navigate through the internal structure of the Object returned from deserialize(...).
SerDeStats	getSerDeStats() Returns statistics collected when serializing
Class<? extends org.apache.hadoop.io.Writable>	getSerializedClass() Returns the Writable class that would be returned by the serialize method.
void	initialize(org.apache.hadoop.conf.Configuration conf, Properties tbl) Initialize the HiveSerializer.
ArrowWrapperWritable	serialize(Object obj, ObjectInspector objInspector) Serialize an object by navigating inside the Object with the ObjectInspector.

Methods inherited from class org.apache.hadoop.hive.serde2.AbstractSerDe

getConfigurationErrors, initialize, shouldStoreFieldsInMetastore

Methods inherited from class java.lang.Object

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

Field Detail

LOG

public static final org.slf4j.Logger LOG

Constructor Detail

ArrowColumnarBatchSerDe

public ArrowColumnarBatchSerDe()

Method Detail

initialize

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

Description copied from class: AbstractSerDe

Initialize the HiveSerializer.

Specified by:

initialize in interface Deserializer

Specified by:

initialize in interface Serializer

Specified by:

initialize in class AbstractSerDe

Parameters:

conf - System properties. Can be null in compile time

tbl - table properties

Throws:

SerDeException

getSerializedClass

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

Description copied from class: AbstractSerDe

Returns the Writable class that would be returned by the serialize method. This is used to initialize SequenceFile header.

Specified by:

getSerializedClass in interface Serializer

Specified by:

getSerializedClass in class AbstractSerDe

serialize

public ArrowWrapperWritable serialize(Object obj,
                                      ObjectInspector objInspector)

Description copied from class: AbstractSerDe

Serialize an object by navigating inside the Object with the ObjectInspector. In most cases, the return value of this function will be constant since the function will reuse the Writable object. If the client wants to keep a copy of the Writable, the client needs to clone the returned value.

Specified by:

serialize in interface Serializer

Specified by:

serialize in class AbstractSerDe

getSerDeStats

public SerDeStats getSerDeStats()

Description copied from class: AbstractSerDe

Returns statistics collected when serializing

Specified by:

getSerDeStats in interface Deserializer

Specified by:

getSerDeStats in interface Serializer

Specified by:

getSerDeStats in class AbstractSerDe

deserialize

public Object deserialize(org.apache.hadoop.io.Writable writable)

Description copied from class: AbstractSerDe

Deserialize an object out of a Writable blob. In most cases, the return value of this function will be constant since the function will reuse the returned object. If the client wants to keep a copy of the object, the client needs to clone the returned value by calling ObjectInspectorUtils.getStandardObject().

Specified by:

deserialize in interface Deserializer

Specified by:

deserialize in class AbstractSerDe

Parameters:

writable - The Writable object containing a serialized object

Returns:

A Java object representing the contents in the blob.

getObjectInspector

public ObjectInspector getObjectInspector()

Description copied from class: AbstractSerDe

Get the object inspector that can be used to navigate through the internal structure of the Object returned from deserialize(...).

Specified by:

getObjectInspector in interface Deserializer

Specified by:

getObjectInspector in class AbstractSerDe