case class Aggregator[K, V, C](createCombiner: (V) => C, mergeValue: (C, V) => C, mergeCombiners: (C, C) => C) extends Product with Serializable
Developer API
A set of functions used to aggregate data.
- createCombiner
function to create the initial value of the aggregation.
- mergeValue
function to merge a new value into the aggregation result.
- mergeCombiners
function to merge outputs from multiple mergeValue function.
- Annotations
- @DeveloperApi()
- Source
- Aggregator.scala
Linear Supertypes
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Inherited
- Aggregator
- Serializable
- Product
- Equals
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Visibility
- Public
- Protected
Instance Constructors
- new Aggregator(createCombiner: (V) => C, mergeValue: (C, V) => C, mergeCombiners: (C, C) => C)
- createCombiner
function to create the initial value of the aggregation.
- mergeValue
function to merge a new value into the aggregation result.
- mergeCombiners
function to merge outputs from multiple mergeValue function.
Value Members
- def combineCombinersByKey(iter: Iterator[_ <: Product2[K, C]], context: TaskContext): Iterator[(K, C)]
- def combineValuesByKey(iter: Iterator[_ <: Product2[K, V]], context: TaskContext): Iterator[(K, C)]
- val createCombiner: (V) => C
- val mergeCombiners: (C, C) => C
- val mergeValue: (C, V) => C
- def productElementNames: Iterator[String]
- Definition Classes
- Product