org.apache.hadoop.hive.ql.io.parquet.read
Class DataWritableReadSupport

java.lang.Object
  parquet.hadoop.api.ReadSupport<org.apache.hadoop.io.ArrayWritable>
      org.apache.hadoop.hive.ql.io.parquet.read.DataWritableReadSupport

public class DataWritableReadSupport
extends parquet.hadoop.api.ReadSupport<org.apache.hadoop.io.ArrayWritable>

A MapWritableReadSupport Manages the translation between Hive and Parquet

Nested Class Summary

Nested classes/interfaces inherited from class parquet.hadoop.api.ReadSupport

parquet.hadoop.api.ReadSupport.ReadContext

Field Summary

static String

HIVE_SCHEMA_KEY

Fields inherited from class parquet.hadoop.api.ReadSupport

PARQUET_READ_SCHEMA

Constructor Summary

DataWritableReadSupport()

Method Summary

parquet.hadoop.api.ReadSupport.ReadContext	init(org.apache.hadoop.conf.Configuration configuration, Map<String,String> keyValueMetaData, parquet.schema.MessageType fileSchema) It creates the readContext for Parquet side with the requested schema during the init phase.
parquet.io.api.RecordMaterializer<org.apache.hadoop.io.ArrayWritable>	prepareForRead(org.apache.hadoop.conf.Configuration configuration, Map<String,String> keyValueMetaData, parquet.schema.MessageType fileSchema, parquet.hadoop.api.ReadSupport.ReadContext readContext) It creates the hive read support to interpret data from parquet to hive

Methods inherited from class parquet.hadoop.api.ReadSupport

getSchemaForRead, getSchemaForRead, init

Methods inherited from class java.lang.Object

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

Field Detail

HIVE_SCHEMA_KEY

public static final String HIVE_SCHEMA_KEY

See Also:

Constant Field Values

Constructor Detail

DataWritableReadSupport

public DataWritableReadSupport()

Method Detail

init

public parquet.hadoop.api.ReadSupport.ReadContext init(org.apache.hadoop.conf.Configuration configuration,
                                                       Map<String,String> keyValueMetaData,
                                                       parquet.schema.MessageType fileSchema)

It creates the readContext for Parquet side with the requested schema during the init phase.

Overrides:

init in class parquet.hadoop.api.ReadSupport<org.apache.hadoop.io.ArrayWritable>

Parameters:

configuration - needed to get the wanted columns

keyValueMetaData - // unused

fileSchema - parquet file schema

Returns:

the parquet ReadContext

prepareForRead

public parquet.io.api.RecordMaterializer<org.apache.hadoop.io.ArrayWritable> prepareForRead(org.apache.hadoop.conf.Configuration configuration,
                                                                                            Map<String,String> keyValueMetaData,
                                                                                            parquet.schema.MessageType fileSchema,
                                                                                            parquet.hadoop.api.ReadSupport.ReadContext readContext)

It creates the hive read support to interpret data from parquet to hive

Specified by:

prepareForRead in class parquet.hadoop.api.ReadSupport<org.apache.hadoop.io.ArrayWritable>

Parameters:

configuration - // unused

keyValueMetaData -

fileSchema - // unused

readContext - containing the requested schema and the schema of the hive table

Returns:

Record Materialize for Hive