Package org.apache.spark
Class NarrowDependency<T>
Object
org.apache.spark.Dependency<T>
org.apache.spark.NarrowDependency<T>
- All Implemented Interfaces:
Serializable
- Direct Known Subclasses:
OneToOneDependency
,RangeDependency
:: DeveloperApi ::
Base class for dependencies where each partition of the child RDD depends on a small number
of partitions of the parent RDD. Narrow dependencies allow for pipelined execution.
- See Also:
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionabstract scala.collection.immutable.Seq<Object>
getParents
(int partitionId) Get the parent partitions for a child partition.rdd()
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Constructor Details
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NarrowDependency
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Method Details
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getParents
Get the parent partitions for a child partition.- Parameters:
partitionId
- a partition of the child RDD- Returns:
- the partitions of the parent RDD that the child partition depends upon
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rdd
- Specified by:
rdd
in classDependency<T>
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