Min (Google Cloud Dataflow SDK 1.9.1 API)

Google Cloud Dataflow SDK for Java, version 1.9.1

Note: If you are using Cloud Dataflow SDK version 2.x, see the Apache Beam API reference documentation.

com.google.cloud.dataflow.sdk.transforms

Class Min

• java.lang.Object
• • com.google.cloud.dataflow.sdk.transforms.Min

• ---

  
  

  public class Min
  extends Object

  PTransforms for computing the minimum of the elements in a PCollection, or the minimum of the values associated with each key in a PCollection of KVs.

  Example 1: get the minimum of a PCollection of Doubles.

   
   PCollection<Double> input = ...;
   PCollection<Double> min = input.apply(Min.doublesGlobally());
    

  Example 2: calculate the minimum of the Integers associated with each unique key (which is of type String).

   
   PCollection<KV<String, Integer>> input = ...;
   PCollection<KV<String, Integer>> minPerKey = input
       .apply(Min.<String>integersPerKey());
    

• • Nested Class Summary

    Nested Classes 

    Modifier and Type	Class and Description
    static class	Min.MinDoubleFn A CombineFn that computes the minimum of a collection of Doubles, useful as an argument to Combine.globally(com.google.cloud.dataflow.sdk.transforms.SerializableFunction<java.lang.Iterable<V>, V>) or Combine.perKey(com.google.cloud.dataflow.sdk.transforms.SerializableFunction<java.lang.Iterable<V>, V>).
    static class	Min.MinFn<T> A CombineFn that computes the maximum of a collection of elements of type T using an arbitrary Comparator, useful as an argument to Combine.globally(com.google.cloud.dataflow.sdk.transforms.SerializableFunction<java.lang.Iterable<V>, V>) or Combine.perKey(com.google.cloud.dataflow.sdk.transforms.SerializableFunction<java.lang.Iterable<V>, V>).
    static class	Min.MinIntegerFn A CombineFn that computes the minimum of a collection of Integers, useful as an argument to Combine.globally(com.google.cloud.dataflow.sdk.transforms.SerializableFunction<java.lang.Iterable<V>, V>) or Combine.perKey(com.google.cloud.dataflow.sdk.transforms.SerializableFunction<java.lang.Iterable<V>, V>).
    static class	Min.MinLongFn A CombineFn that computes the minimum of a collection of Longs, useful as an argument to Combine.globally(com.google.cloud.dataflow.sdk.transforms.SerializableFunction<java.lang.Iterable<V>, V>) or Combine.perKey(com.google.cloud.dataflow.sdk.transforms.SerializableFunction<java.lang.Iterable<V>, V>).

  • Method Summary

    All Methods Static Methods Concrete Methods 

    Modifier and Type	Method and Description
    static Combine.Globally<Double,Double>	doublesGlobally() Returns a PTransform that takes an input PCollection<Double> and returns a PCollection<Double> whose contents is the minimum of the input PCollection's elements, or Double.POSITIVE_INFINITY if there are no elements.
    static <K> Combine.PerKey<K,Double,Double>	doublesPerKey() Returns a PTransform that takes an input PCollection<KV<K, Double>> and returns a PCollection<KV<K, Double>> that contains an output element mapping each distinct key in the input PCollection to the minimum of the values associated with that key in the input PCollection.
    static <T extends Comparable<? super T>> Combine.Globally<T,T>	globally() Returns a PTransform that takes an input PCollection<T> and returns a PCollection<T> whose contents is the minimum according to the natural ordering of T of the input PCollection's elements, or null if there are no elements.
    static <T,ComparatorT extends Comparator<? super T> & Serializable> Combine.Globally<T,T>	globally(ComparatorT comparator) Returns a PTransform that takes an input PCollection<T> and returns a PCollection<T> whose contents is the minimum of the input PCollection's elements, or null if there are no elements.
    static Combine.Globally<Integer,Integer>	integersGlobally() Returns a PTransform that takes an input PCollection<Integer> and returns a PCollection<Integer> whose contents is a single value that is the minimum of the input PCollection's elements, or Integer.MAX_VALUE if there are no elements.
    static <K> Combine.PerKey<K,Integer,Integer>	integersPerKey() Returns a PTransform that takes an input PCollection<KV<K, Integer>> and returns a PCollection<KV<K, Integer>> that contains an output element mapping each distinct key in the input PCollection to the minimum of the values associated with that key in the input PCollection.
    static Combine.Globally<Long,Long>	longsGlobally() Returns a PTransform that takes an input PCollection<Long> and returns a PCollection<Long> whose contents is the minimum of the input PCollection's elements, or Long.MAX_VALUE if there are no elements.
    static <K> Combine.PerKey<K,Long,Long>	longsPerKey() Returns a PTransform that takes an input PCollection<KV<K, Long>> and returns a PCollection<KV<K, Long>> that contains an output element mapping each distinct key in the input PCollection to the minimum of the values associated with that key in the input PCollection.
    static <K,T extends Comparable<? super T>> Combine.PerKey<K,T,T>	perKey() Returns a PTransform that takes an input PCollection<KV<K, T>> and returns a PCollection<KV<K, T>> that contains an output element mapping each distinct key in the input PCollection to the minimum according to the natural ordering of T of the values associated with that key in the input PCollection.
    static <K,T,ComparatorT extends Comparator<? super T> & Serializable> Combine.PerKey<K,T,T>	perKey(ComparatorT comparator) Returns a PTransform that takes an input PCollection<KV<K, T>> and returns a PCollection<KV<K, T>> that contains one output element per key mapping each to the minimum of the values associated with that key in the input PCollection.

    • Methods inherited from class java.lang.Object

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

• • Method Detail

    • integersGlobally

      public static Combine.Globally<Integer,Integer> integersGlobally()

      Returns a PTransform that takes an input PCollection<Integer> and returns a PCollection<Integer> whose contents is a single value that is the minimum of the input PCollection's elements, or Integer.MAX_VALUE if there are no elements.

    • integersPerKey

      public static <K> Combine.PerKey<K,Integer,Integer> integersPerKey()

      Returns a PTransform that takes an input PCollection<KV<K, Integer>> and returns a PCollection<KV<K, Integer>> that contains an output element mapping each distinct key in the input PCollection to the minimum of the values associated with that key in the input PCollection.

      See Combine.PerKey for how this affects timestamps and windowing.

    • longsGlobally

      public static Combine.Globally<Long,Long> longsGlobally()

      Returns a PTransform that takes an input PCollection<Long> and returns a PCollection<Long> whose contents is the minimum of the input PCollection's elements, or Long.MAX_VALUE if there are no elements.

    • longsPerKey

      public static <K> Combine.PerKey<K,Long,Long> longsPerKey()

      Returns a PTransform that takes an input PCollection<KV<K, Long>> and returns a PCollection<KV<K, Long>> that contains an output element mapping each distinct key in the input PCollection to the minimum of the values associated with that key in the input PCollection.

      See Combine.PerKey for how this affects timestamps and windowing.

    • doublesGlobally

      public static Combine.Globally<Double,Double> doublesGlobally()

      Returns a PTransform that takes an input PCollection<Double> and returns a PCollection<Double> whose contents is the minimum of the input PCollection's elements, or Double.POSITIVE_INFINITY if there are no elements.

    • doublesPerKey

      public static <K> Combine.PerKey<K,Double,Double> doublesPerKey()

      Returns a PTransform that takes an input PCollection<KV<K, Double>> and returns a PCollection<KV<K, Double>> that contains an output element mapping each distinct key in the input PCollection to the minimum of the values associated with that key in the input PCollection.

      See Combine.PerKey for how this affects timestamps and windowing.

    • globally

      public static <T extends Comparable<? super T>> Combine.Globally<T,T> globally()

      Returns a PTransform that takes an input PCollection<T> and returns a PCollection<T> whose contents is the minimum according to the natural ordering of T of the input PCollection's elements, or null if there are no elements.

    • perKey

      public static <K,T extends Comparable<? super T>> Combine.PerKey<K,T,T> perKey()

      Returns a PTransform that takes an input PCollection<KV<K, T>> and returns a PCollection<KV<K, T>> that contains an output element mapping each distinct key in the input PCollection to the minimum according to the natural ordering of T of the values associated with that key in the input PCollection.

      See Combine.PerKey for how this affects timestamps and windowing.

    • globally

      public static <T,ComparatorT extends Comparator<? super T> & Serializable> Combine.Globally<T,T> globally(ComparatorT comparator)

      Returns a PTransform that takes an input PCollection<T> and returns a PCollection<T> whose contents is the minimum of the input PCollection's elements, or null if there are no elements.

    • perKey

      public static <K,T,ComparatorT extends Comparator<? super T> & Serializable> Combine.PerKey<K,T,T> perKey(ComparatorT comparator)

      Returns a PTransform that takes an input PCollection<KV<K, T>> and returns a PCollection<KV<K, T>> that contains one output element per key mapping each to the minimum of the values associated with that key in the input PCollection.

      See Combine.PerKey for how this affects timestamps and windowing.