org.apache.spark.sql.hive

Class HadoopTableReader

Object

org.apache.spark.sql.hive.HadoopTableReader

All Implemented Interfaces:

TableReader

public class HadoopTableReader
extends Object
implements TableReader

Helper class for scanning tables stored in Hadoop - e.g., to read Hive tables that reside in the data warehouse directory.

Constructor Summary

Constructors

Constructor and Description
HadoopTableReader(scala.collection.Seq<org.apache.spark.sql.catalyst.expressions.Attribute> attributes, MetastoreRelation relation, HiveContext sc, org.apache.hadoop.hive.conf.HiveConf hiveExtraConf)

Method Summary

Methods

Modifier and Type	Method and Description
static scala.collection.Iterator<org.apache.spark.sql.Row>	fillObject(scala.collection.Iterator<org.apache.hadoop.io.Writable> iterator, org.apache.hadoop.hive.serde2.Deserializer deserializer, scala.collection.Seq<scala.Tuple2<org.apache.spark.sql.catalyst.expressions.Attribute,Object>> nonPartitionKeyAttrs, org.apache.spark.sql.catalyst.expressions.MutableRow mutableRow) Transform all given raw Writables into Rows.
static void	initializeLocalJobConfFunc(String path, org.apache.hadoop.hive.ql.plan.TableDesc tableDesc, org.apache.hadoop.mapred.JobConf jobConf) Curried.
RDD<org.apache.spark.sql.Row>	makeRDDForPartitionedTable(scala.collection.immutable.Map<org.apache.hadoop.hive.ql.metadata.Partition,Class<? extends org.apache.hadoop.hive.serde2.Deserializer>> partitionToDeserializer, scala.Option<org.apache.hadoop.fs.PathFilter> filterOpt) Create a HadoopRDD for every partition key specified in the query.
RDD<org.apache.spark.sql.Row>	makeRDDForPartitionedTable(scala.collection.Seq<org.apache.hadoop.hive.ql.metadata.Partition> partitions)
RDD<org.apache.spark.sql.Row>	makeRDDForTable(org.apache.hadoop.hive.ql.metadata.Table hiveTable)
RDD<org.apache.spark.sql.Row>	makeRDDForTable(org.apache.hadoop.hive.ql.metadata.Table hiveTable, Class<? extends org.apache.hadoop.hive.serde2.Deserializer> deserializerClass, scala.Option<org.apache.hadoop.fs.PathFilter> filterOpt) Creates a Hadoop RDD to read data from the target table's data directory.

Methods inherited from class Object

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

Constructor Detail

HadoopTableReader

public HadoopTableReader(scala.collection.Seq<org.apache.spark.sql.catalyst.expressions.Attribute> attributes,
                 MetastoreRelation relation,
                 HiveContext sc,
                 org.apache.hadoop.hive.conf.HiveConf hiveExtraConf)

Method Detail

initializeLocalJobConfFunc

public static void initializeLocalJobConfFunc(String path,
                              org.apache.hadoop.hive.ql.plan.TableDesc tableDesc,
                              org.apache.hadoop.mapred.JobConf jobConf)

Curried. After given an argument for 'path', the resulting JobConf => Unit closure is used to instantiate a HadoopRDD.

fillObject

public static scala.collection.Iterator<org.apache.spark.sql.Row> fillObject(scala.collection.Iterator<org.apache.hadoop.io.Writable> iterator,
                                                             org.apache.hadoop.hive.serde2.Deserializer deserializer,
                                                             scala.collection.Seq<scala.Tuple2<org.apache.spark.sql.catalyst.expressions.Attribute,Object>> nonPartitionKeyAttrs,
                                                             org.apache.spark.sql.catalyst.expressions.MutableRow mutableRow)

Transform all given raw Writables into Rows.

Parameters:

iterator - Iterator of all Writables to be transformed

deserializer - The Deserializer associated with the input Writable

nonPartitionKeyAttrs - Attributes that should be filled together with their corresponding positions in the output schema

mutableRow - A reusable MutableRow that should be filled

Returns:

An Iterator[Row] transformed from iterator

makeRDDForTable

public RDD<org.apache.spark.sql.Row> makeRDDForTable(org.apache.hadoop.hive.ql.metadata.Table hiveTable)

Specified by:

makeRDDForTable in interface TableReader

makeRDDForTable

public RDD<org.apache.spark.sql.Row> makeRDDForTable(org.apache.hadoop.hive.ql.metadata.Table hiveTable,
                                            Class<? extends org.apache.hadoop.hive.serde2.Deserializer> deserializerClass,
                                            scala.Option<org.apache.hadoop.fs.PathFilter> filterOpt)

Creates a Hadoop RDD to read data from the target table's data directory. Returns a transformed RDD that contains deserialized rows.

Parameters:

hiveTable - Hive metadata for the table being scanned.

deserializerClass - Class of the SerDe used to deserialize Writables read from Hadoop.

filterOpt - If defined, then the filter is used to reject files contained in the data directory being read. If None, then all files are accepted.

makeRDDForPartitionedTable

public RDD<org.apache.spark.sql.Row> makeRDDForPartitionedTable(scala.collection.Seq<org.apache.hadoop.hive.ql.metadata.Partition> partitions)

Specified by:

makeRDDForPartitionedTable in interface TableReader

makeRDDForPartitionedTable

public RDD<org.apache.spark.sql.Row> makeRDDForPartitionedTable(scala.collection.immutable.Map<org.apache.hadoop.hive.ql.metadata.Partition,Class<? extends org.apache.hadoop.hive.serde2.Deserializer>> partitionToDeserializer,
                                                       scala.Option<org.apache.hadoop.fs.PathFilter> filterOpt)

Create a HadoopRDD for every partition key specified in the query. Note that for on-disk Hive tables, a data directory is created for each partition corresponding to keys specified using 'PARTITION BY'.

Parameters:

partitionToDeserializer - Mapping from a Hive Partition metadata object to the SerDe class to use to deserialize input Writables from the corresponding partition.

filterOpt - If defined, then the filter is used to reject files contained in the data subdirectory of each partition being read. If None, then all files are accepted.