Package org.apache.spark.sql

Class KeyValueGroupedDataset<K,V>

Object
org.apache.spark.sql.KeyValueGroupedDataset<K,V>
All Implemented Interfaces:
Serializable, scala.Serializable
public class KeyValueGroupedDataset<K,V> extends Object implements scala.Serializable
A Dataset has been logically grouped by a user specified grouping key. Users should not construct a KeyValueGroupedDataset directly, but should instead call groupByKey on an existing Dataset.

Since:
2.0.0
See Also:

  • Method Details

    • agg

      public <U1> Dataset<scala.Tuple2<K,U1>> agg(TypedColumn<V,U1> col1)
      Computes the given aggregation, returning a Dataset of tuples for each unique key and the result of computing this aggregation over all elements in the group.

      Parameters:
      col1 - (undocumented)
      Returns:
      (undocumented)
      Since:
      1.6.0

    • agg

      public <U1, U2> Dataset<scala.Tuple3<K,U1,U2>> agg(TypedColumn<V,U1> col1, TypedColumn<V,U2> col2)
      Computes the given aggregations, returning a Dataset of tuples for each unique key and the result of computing these aggregations over all elements in the group.

      Parameters:
      col1 - (undocumented)
      col2 - (undocumented)
      Returns:
      (undocumented)
      Since:
      1.6.0

    • agg

      public <U1, U2, U3> Dataset<scala.Tuple4<K,U1,U2,U3>> agg(TypedColumn<V,U1> col1, TypedColumn<V,U2> col2, TypedColumn<V,U3> col3)
      Computes the given aggregations, returning a Dataset of tuples for each unique key and the result of computing these aggregations over all elements in the group.

      Parameters:
      col1 - (undocumented)
      col2 - (undocumented)
      col3 - (undocumented)
      Returns:
      (undocumented)
      Since:
      1.6.0

    • agg

      public <U1, U2, U3, U4> Dataset<scala.Tuple5<K,U1,U2,U3,U4>> agg(TypedColumn<V,U1> col1, TypedColumn<V,U2> col2, TypedColumn<V,U3> col3, TypedColumn<V,U4> col4)
      Computes the given aggregations, returning a Dataset of tuples for each unique key and the result of computing these aggregations over all elements in the group.

      Parameters:
      col1 - (undocumented)
      col2 - (undocumented)
      col3 - (undocumented)
      col4 - (undocumented)
      Returns:
      (undocumented)
      Since:
      1.6.0

    • agg

      public <U1, U2, U3, U4, U5> Dataset<scala.Tuple6<K,U1,U2,U3,U4,U5>> agg(TypedColumn<V,U1> col1, TypedColumn<V,U2> col2, TypedColumn<V,U3> col3, TypedColumn<V,U4> col4, TypedColumn<V,U5> col5)
      Computes the given aggregations, returning a Dataset of tuples for each unique key and the result of computing these aggregations over all elements in the group.

      Parameters:
      col1 - (undocumented)
      col2 - (undocumented)
      col3 - (undocumented)
      col4 - (undocumented)
      col5 - (undocumented)
      Returns:
      (undocumented)
      Since:
      3.0.0

    • agg

      public <U1, U2, U3, U4, U5, U6> Dataset<scala.Tuple7<K,U1,U2,U3,U4,U5,U6>> agg(TypedColumn<V,U1> col1, TypedColumn<V,U2> col2, TypedColumn<V,U3> col3, TypedColumn<V,U4> col4, TypedColumn<V,U5> col5, TypedColumn<V,U6> col6)
      Computes the given aggregations, returning a Dataset of tuples for each unique key and the result of computing these aggregations over all elements in the group.

      Parameters:
      col1 - (undocumented)
      col2 - (undocumented)
      col3 - (undocumented)
      col4 - (undocumented)
      col5 - (undocumented)
      col6 - (undocumented)
      Returns:
      (undocumented)
      Since:
      3.0.0

    • agg

      public <U1, U2, U3, U4, U5, U6, U7> Dataset<scala.Tuple8<K,U1,U2,U3,U4,U5,U6,U7>> agg(TypedColumn<V,U1> col1, TypedColumn<V,U2> col2, TypedColumn<V,U3> col3, TypedColumn<V,U4> col4, TypedColumn<V,U5> col5, TypedColumn<V,U6> col6, TypedColumn<V,U7> col7)
      Computes the given aggregations, returning a Dataset of tuples for each unique key and the result of computing these aggregations over all elements in the group.

      Parameters:
      col1 - (undocumented)
      col2 - (undocumented)
      col3 - (undocumented)
      col4 - (undocumented)
      col5 - (undocumented)
      col6 - (undocumented)
      col7 - (undocumented)
      Returns:
      (undocumented)
      Since:
      3.0.0

    • agg

      public <U1, U2, U3, U4, U5, U6, U7, U8> Dataset<scala.Tuple9<K,U1,U2,U3,U4,U5,U6,U7,U8>> agg(TypedColumn<V,U1> col1, TypedColumn<V,U2> col2, TypedColumn<V,U3> col3, TypedColumn<V,U4> col4, TypedColumn<V,U5> col5, TypedColumn<V,U6> col6, TypedColumn<V,U7> col7, TypedColumn<V,U8> col8)
      Computes the given aggregations, returning a Dataset of tuples for each unique key and the result of computing these aggregations over all elements in the group.

      Parameters:
      col1 - (undocumented)
      col2 - (undocumented)
      col3 - (undocumented)
      col4 - (undocumented)
      col5 - (undocumented)
      col6 - (undocumented)
      col7 - (undocumented)
      col8 - (undocumented)
      Returns:
      (undocumented)
      Since:
      3.0.0

    • cogroup

      public <U, R> Dataset<R> cogroup(KeyValueGroupedDataset<K,U> other, scala.Function3<K,scala.collection.Iterator<V>,scala.collection.Iterator<U>,scala.collection.TraversableOnce<R>> f, Encoder<R> evidence$16)
      (Scala-specific) Applies the given function to each cogrouped data. For each unique group, the function will be passed the grouping key and 2 iterators containing all elements in the group from Dataset this and other. The function can return an iterator containing elements of an arbitrary type which will be returned as a new Dataset.

      Parameters:
      other - (undocumented)
      f - (undocumented)
      evidence$16 - (undocumented)
      Returns:
      (undocumented)
      Since:
      1.6.0

    • cogroup

      public <U, R> Dataset<R> cogroup(KeyValueGroupedDataset<K,U> other, CoGroupFunction<K,V,U,R> f, Encoder<R> encoder)
      (Java-specific) Applies the given function to each cogrouped data. For each unique group, the function will be passed the grouping key and 2 iterators containing all elements in the group from Dataset this and other. The function can return an iterator containing elements of an arbitrary type which will be returned as a new Dataset.

      Parameters:
      other - (undocumented)
      f - (undocumented)
      encoder - (undocumented)
      Returns:
      (undocumented)
      Since:
      1.6.0

    • cogroupSorted

      public <U, R> Dataset<R> cogroupSorted(KeyValueGroupedDataset<K,U> other, scala.collection.Seq<Column> thisSortExprs, scala.collection.Seq<Column> otherSortExprs, scala.Function3<K,scala.collection.Iterator<V>,scala.collection.Iterator<U>,scala.collection.TraversableOnce<R>> f, Encoder<R> evidence$17)
      (Scala-specific) Applies the given function to each sorted cogrouped data. For each unique group, the function will be passed the grouping key and 2 sorted iterators containing all elements in the group from Dataset this and other. The function can return an iterator containing elements of an arbitrary type which will be returned as a new Dataset.

      This is equivalent to cogroup(org.apache.spark.sql.KeyValueGroupedDataset<K, U>, scala.Function3<K, scala.collection.Iterator<V>, scala.collection.Iterator<U>, scala.collection.TraversableOnce<R>>, org.apache.spark.sql.Encoder<R>), except for the iterators to be sorted according to the given sort expressions. That sorting does not add computational complexity.

      Parameters:
      other - (undocumented)
      thisSortExprs - (undocumented)
      otherSortExprs - (undocumented)
      f - (undocumented)
      evidence$17 - (undocumented)
      Returns:
      (undocumented)
      Since:
      3.4.0
      See Also:

    • cogroupSorted

      public <U, R> Dataset<R> cogroupSorted(KeyValueGroupedDataset<K,U> other, Column[] thisSortExprs, Column[] otherSortExprs, CoGroupFunction<K,V,U,R> f, Encoder<R> encoder)
      (Java-specific) Applies the given function to each sorted cogrouped data. For each unique group, the function will be passed the grouping key and 2 sorted iterators containing all elements in the group from Dataset this and other. The function can return an iterator containing elements of an arbitrary type which will be returned as a new Dataset.

      This is equivalent to cogroup(org.apache.spark.sql.KeyValueGroupedDataset<K, U>, scala.Function3<K, scala.collection.Iterator<V>, scala.collection.Iterator<U>, scala.collection.TraversableOnce<R>>, org.apache.spark.sql.Encoder<R>), except for the iterators to be sorted according to the given sort expressions. That sorting does not add computational complexity.

      Parameters:
      other - (undocumented)
      thisSortExprs - (undocumented)
      otherSortExprs - (undocumented)
      f - (undocumented)
      encoder - (undocumented)
      Returns:
      (undocumented)
      Since:
      3.4.0
      See Also:

    • count

      public Dataset<scala.Tuple2<K,Object>> count()
      Returns a Dataset that contains a tuple with each key and the number of items present for that key.

      Returns:
      (undocumented)
      Since:
      1.6.0

    • flatMapGroups

      public <U> Dataset<U> flatMapGroups(scala.Function2<K,scala.collection.Iterator<V>,scala.collection.TraversableOnce<U>> f, Encoder<U> evidence$3)
      (Scala-specific) Applies the given function to each group of data. For each unique group, the function will be passed the group key and an iterator that contains all of the elements in the group. The function can return an iterator containing elements of an arbitrary type which will be returned as a new Dataset.

      This function does not support partial aggregation, and as a result requires shuffling all the data in the Dataset. If an application intends to perform an aggregation over each key, it is best to use the reduce function or an org.apache.spark.sql.expressions#Aggregator.

      Internally, the implementation will spill to disk if any given group is too large to fit into memory. However, users must take care to avoid materializing the whole iterator for a group (for example, by calling toList) unless they are sure that this is possible given the memory constraints of their cluster.

      Parameters:
      f - (undocumented)
      evidence$3 - (undocumented)
      Returns:
      (undocumented)
      Since:
      1.6.0

    • flatMapGroups

      public <U> Dataset<U> flatMapGroups(FlatMapGroupsFunction<K,V,U> f, Encoder<U> encoder)
      (Java-specific) Applies the given function to each group of data. For each unique group, the function will be passed the group key and an iterator that contains all of the elements in the group. The function can return an iterator containing elements of an arbitrary type which will be returned as a new Dataset.

      This function does not support partial aggregation, and as a result requires shuffling all the data in the Dataset. If an application intends to perform an aggregation over each key, it is best to use the reduce function or an org.apache.spark.sql.expressions#Aggregator.

      Internally, the implementation will spill to disk if any given group is too large to fit into memory. However, users must take care to avoid materializing the whole iterator for a group (for example, by calling toList) unless they are sure that this is possible given the memory constraints of their cluster.

      Parameters:
      f - (undocumented)
      encoder - (undocumented)
      Returns:
      (undocumented)
      Since:
      1.6.0

    • flatMapGroupsWithState

      public <S, U> Dataset<U> flatMapGroupsWithState(OutputMode outputMode, GroupStateTimeout timeoutConf, scala.Function3<K,scala.collection.Iterator<V>,GroupState<S>,scala.collection.Iterator<U>> func, Encoder<S> evidence$12, Encoder<U> evidence$13)
      (Scala-specific) Applies the given function to each group of data, while maintaining a user-defined per-group state. The result Dataset will represent the objects returned by the function. For a static batch Dataset, the function will be invoked once per group. For a streaming Dataset, the function will be invoked for each group repeatedly in every trigger, and updates to each group's state will be saved across invocations. See GroupState for more details.

      Parameters:
      func - Function to be called on every group.
      outputMode - The output mode of the function.
      timeoutConf - Timeout configuration for groups that do not receive data for a while.

      See Encoder for more details on what types are encodable to Spark SQL.

      evidence$12 - (undocumented)
      evidence$13 - (undocumented)
      Returns:
      (undocumented)
      Since:
      2.2.0

    • flatMapGroupsWithState

      public <S, U> Dataset<U> flatMapGroupsWithState(OutputMode outputMode, GroupStateTimeout timeoutConf, KeyValueGroupedDataset<K,S> initialState, scala.Function3<K,scala.collection.Iterator<V>,GroupState<S>,scala.collection.Iterator<U>> func, Encoder<S> evidence$14, Encoder<U> evidence$15)
      (Scala-specific) Applies the given function to each group of data, while maintaining a user-defined per-group state. The result Dataset will represent the objects returned by the function. For a static batch Dataset, the function will be invoked once per group. For a streaming Dataset, the function will be invoked for each group repeatedly in every trigger, and updates to each group's state will be saved across invocations. See GroupState for more details.

      Parameters:
      func - Function to be called on every group.
      outputMode - The output mode of the function.
      timeoutConf - Timeout configuration for groups that do not receive data for a while.
      initialState - The user provided state that will be initialized when the first batch of data is processed in the streaming query. The user defined function will be called on the state data even if there are no other values in the group. To covert a Dataset ds of type of type Dataset[(K, S)] to a KeyValueGroupedDataset[K, S], use 
       ds.groupByKey(x => x._1).mapValues(_._2)
      See {@link Encoder} for more details on what types are encodable to Spark SQL. @since 3.2.0
      evidence$14 - (undocumented)
      evidence$15 - (undocumented)
      Returns:
      (undocumented)

    • flatMapGroupsWithState

      public <S, U> Dataset<U> flatMapGroupsWithState(FlatMapGroupsWithStateFunction<K,V,S,U> func, OutputMode outputMode, Encoder<S> stateEncoder, Encoder<U> outputEncoder, GroupStateTimeout timeoutConf)
      (Java-specific) Applies the given function to each group of data, while maintaining a user-defined per-group state. The result Dataset will represent the objects returned by the function. For a static batch Dataset, the function will be invoked once per group. For a streaming Dataset, the function will be invoked for each group repeatedly in every trigger, and updates to each group's state will be saved across invocations. See GroupState for more details.

      Parameters:
      func - Function to be called on every group.
      outputMode - The output mode of the function.
      stateEncoder - Encoder for the state type.
      outputEncoder - Encoder for the output type.
      timeoutConf - Timeout configuration for groups that do not receive data for a while.

      See Encoder for more details on what types are encodable to Spark SQL.

      Returns:
      (undocumented)
      Since:
      2.2.0

    • flatMapGroupsWithState

      public <S, U> Dataset<U> flatMapGroupsWithState(FlatMapGroupsWithStateFunction<K,V,S,U> func, OutputMode outputMode, Encoder<S> stateEncoder, Encoder<U> outputEncoder, GroupStateTimeout timeoutConf, KeyValueGroupedDataset<K,S> initialState)
      (Java-specific) Applies the given function to each group of data, while maintaining a user-defined per-group state. The result Dataset will represent the objects returned by the function. For a static batch Dataset, the function will be invoked once per group. For a streaming Dataset, the function will be invoked for each group repeatedly in every trigger, and updates to each group's state will be saved across invocations. See GroupState for more details.

      Parameters:
      func - Function to be called on every group.
      outputMode - The output mode of the function.
      stateEncoder - Encoder for the state type.
      outputEncoder - Encoder for the output type.
      timeoutConf - Timeout configuration for groups that do not receive data for a while.
      initialState - The user provided state that will be initialized when the first batch of data is processed in the streaming query. The user defined function will be called on the state data even if there are no other values in the group. To covert a Dataset ds of type of type Dataset[(K, S)] to a KeyValueGroupedDataset[K, S], use 
       ds.groupByKey(x => x._1).mapValues(_._2)
      See {@link Encoder} for more details on what types are encodable to Spark SQL. @since 3.2.0
      Returns:
      (undocumented)

    • flatMapSortedGroups

      public <U> Dataset<U> flatMapSortedGroups(scala.collection.Seq<Column> sortExprs, scala.Function2<K,scala.collection.Iterator<V>,scala.collection.TraversableOnce<U>> f, Encoder<U> evidence$4)
      (Scala-specific) Applies the given function to each group of data. For each unique group, the function will be passed the group key and a sorted iterator that contains all of the elements in the group. The function can return an iterator containing elements of an arbitrary type which will be returned as a new Dataset.

      This function does not support partial aggregation, and as a result requires shuffling all the data in the Dataset. If an application intends to perform an aggregation over each key, it is best to use the reduce function or an org.apache.spark.sql.expressions#Aggregator.

      Internally, the implementation will spill to disk if any given group is too large to fit into memory. However, users must take care to avoid materializing the whole iterator for a group (for example, by calling toList) unless they are sure that this is possible given the memory constraints of their cluster.

      This is equivalent to flatMapGroups(scala.Function2<K, scala.collection.Iterator<V>, scala.collection.TraversableOnce<U>>, org.apache.spark.sql.Encoder<U>), except for the iterator to be sorted according to the given sort expressions. That sorting does not add computational complexity.

      Parameters:
      sortExprs - (undocumented)
      f - (undocumented)
      evidence$4 - (undocumented)
      Returns:
      (undocumented)
      Since:
      3.4.0
      See Also:

    • flatMapSortedGroups

      public <U> Dataset<U> flatMapSortedGroups(Column[] SortExprs, FlatMapGroupsFunction<K,V,U> f, Encoder<U> encoder)
      (Java-specific) Applies the given function to each group of data. For each unique group, the function will be passed the group key and a sorted iterator that contains all of the elements in the group. The function can return an iterator containing elements of an arbitrary type which will be returned as a new Dataset.

      This function does not support partial aggregation, and as a result requires shuffling all the data in the Dataset. If an application intends to perform an aggregation over each key, it is best to use the reduce function or an org.apache.spark.sql.expressions#Aggregator.

      Internally, the implementation will spill to disk if any given group is too large to fit into memory. However, users must take care to avoid materializing the whole iterator for a group (for example, by calling toList) unless they are sure that this is possible given the memory constraints of their cluster.

      This is equivalent to flatMapGroups(scala.Function2<K, scala.collection.Iterator<V>, scala.collection.TraversableOnce<U>>, org.apache.spark.sql.Encoder<U>), except for the iterator to be sorted according to the given sort expressions. That sorting does not add computational complexity.

      Parameters:
      SortExprs - (undocumented)
      f - (undocumented)
      encoder - (undocumented)
      Returns:
      (undocumented)
      Since:
      3.4.0
      See Also:

    • keyAs

      public <L> KeyValueGroupedDataset<L,V> keyAs(Encoder<L> evidence$1)
      Returns a new KeyValueGroupedDataset where the type of the key has been mapped to the specified type. The mapping of key columns to the type follows the same rules as as on Dataset.

      Parameters:
      evidence$1 - (undocumented)
      Returns:
      (undocumented)
      Since:
      1.6.0

    • keys

      public Dataset<K> keys()
      Returns a Dataset that contains each unique key. This is equivalent to doing mapping over the Dataset to extract the keys and then running a distinct operation on those.

      Returns:
      (undocumented)
      Since:
      1.6.0

    • mapGroups

      public <U> Dataset<U> mapGroups(scala.Function2<K,scala.collection.Iterator<V>,U> f, Encoder<U> evidence$5)
      (Scala-specific) Applies the given function to each group of data. For each unique group, the function will be passed the group key and an iterator that contains all of the elements in the group. The function can return an element of arbitrary type which will be returned as a new Dataset.

      This function does not support partial aggregation, and as a result requires shuffling all the data in the Dataset. If an application intends to perform an aggregation over each key, it is best to use the reduce function or an org.apache.spark.sql.expressions#Aggregator.

      Internally, the implementation will spill to disk if any given group is too large to fit into memory. However, users must take care to avoid materializing the whole iterator for a group (for example, by calling toList) unless they are sure that this is possible given the memory constraints of their cluster.

      Parameters:
      f - (undocumented)
      evidence$5 - (undocumented)
      Returns:
      (undocumented)
      Since:
      1.6.0

    • mapGroups

      public <U> Dataset<U> mapGroups(MapGroupsFunction<K,V,U> f, Encoder<U> encoder)
      (Java-specific) Applies the given function to each group of data. For each unique group, the function will be passed the group key and an iterator that contains all of the elements in the group. The function can return an element of arbitrary type which will be returned as a new Dataset.

      This function does not support partial aggregation, and as a result requires shuffling all the data in the Dataset. If an application intends to perform an aggregation over each key, it is best to use the reduce function or an org.apache.spark.sql.expressions#Aggregator.

      Internally, the implementation will spill to disk if any given group is too large to fit into memory. However, users must take care to avoid materializing the whole iterator for a group (for example, by calling toList) unless they are sure that this is possible given the memory constraints of their cluster.

      Parameters:
      f - (undocumented)
      encoder - (undocumented)
      Returns:
      (undocumented)
      Since:
      1.6.0

    • mapGroupsWithState

      public <S, U> Dataset<U> mapGroupsWithState(scala.Function3<K,scala.collection.Iterator<V>,GroupState<S>,U> func, Encoder<S> evidence$6, Encoder<U> evidence$7)
      (Scala-specific) Applies the given function to each group of data, while maintaining a user-defined per-group state. The result Dataset will represent the objects returned by the function. For a static batch Dataset, the function will be invoked once per group. For a streaming Dataset, the function will be invoked for each group repeatedly in every trigger, and updates to each group's state will be saved across invocations. See GroupState for more details.

      Parameters:
      func - Function to be called on every group.

      See Encoder for more details on what types are encodable to Spark SQL.

      evidence$6 - (undocumented)
      evidence$7 - (undocumented)
      Returns:
      (undocumented)
      Since:
      2.2.0

    • mapGroupsWithState

      public <S, U> Dataset<U> mapGroupsWithState(GroupStateTimeout timeoutConf, scala.Function3<K,scala.collection.Iterator<V>,GroupState<S>,U> func, Encoder<S> evidence$8, Encoder<U> evidence$9)
      (Scala-specific) Applies the given function to each group of data, while maintaining a user-defined per-group state. The result Dataset will represent the objects returned by the function. For a static batch Dataset, the function will be invoked once per group. For a streaming Dataset, the function will be invoked for each group repeatedly in every trigger, and updates to each group's state will be saved across invocations. See GroupState for more details.

      Parameters:
      func - Function to be called on every group.
      timeoutConf - Timeout configuration for groups that do not receive data for a while.

      See Encoder for more details on what types are encodable to Spark SQL.

      evidence$8 - (undocumented)
      evidence$9 - (undocumented)
      Returns:
      (undocumented)
      Since:
      2.2.0

    • mapGroupsWithState

      public <S, U> Dataset<U> mapGroupsWithState(GroupStateTimeout timeoutConf, KeyValueGroupedDataset<K,S> initialState, scala.Function3<K,scala.collection.Iterator<V>,GroupState<S>,U> func, Encoder<S> evidence$10, Encoder<U> evidence$11)
      (Scala-specific) Applies the given function to each group of data, while maintaining a user-defined per-group state. The result Dataset will represent the objects returned by the function. For a static batch Dataset, the function will be invoked once per group. For a streaming Dataset, the function will be invoked for each group repeatedly in every trigger, and updates to each group's state will be saved across invocations. See GroupState for more details.

      Parameters:
      func - Function to be called on every group.
      timeoutConf - Timeout Conf, see GroupStateTimeout for more details
      initialState - The user provided state that will be initialized when the first batch of data is processed in the streaming query. The user defined function will be called on the state data even if there are no other values in the group. To convert a Dataset ds of type Dataset[(K, S)] to a KeyValueGroupedDataset[K, S] do 
       ds.groupByKey(x => x._1).mapValues(_._2)
      See {@link Encoder} for more details on what types are encodable to Spark SQL. @since 3.2.0
      evidence$10 - (undocumented)
      evidence$11 - (undocumented)
      Returns:
      (undocumented)

    • mapGroupsWithState

      public <S, U> Dataset<U> mapGroupsWithState(MapGroupsWithStateFunction<K,V,S,U> func, Encoder<S> stateEncoder, Encoder<U> outputEncoder)
      (Java-specific) Applies the given function to each group of data, while maintaining a user-defined per-group state. The result Dataset will represent the objects returned by the function. For a static batch Dataset, the function will be invoked once per group. For a streaming Dataset, the function will be invoked for each group repeatedly in every trigger, and updates to each group's state will be saved across invocations. See GroupState for more details.

      Parameters:
      func - Function to be called on every group.
      stateEncoder - Encoder for the state type.
      outputEncoder - Encoder for the output type.

      See Encoder for more details on what types are encodable to Spark SQL.

      Returns:
      (undocumented)
      Since:
      2.2.0

    • mapGroupsWithState

      public <S, U> Dataset<U> mapGroupsWithState(MapGroupsWithStateFunction<K,V,S,U> func, Encoder<S> stateEncoder, Encoder<U> outputEncoder, GroupStateTimeout timeoutConf)
      (Java-specific) Applies the given function to each group of data, while maintaining a user-defined per-group state. The result Dataset will represent the objects returned by the function. For a static batch Dataset, the function will be invoked once per group. For a streaming Dataset, the function will be invoked for each group repeatedly in every trigger, and updates to each group's state will be saved across invocations. See GroupState for more details.

      Parameters:
      func - Function to be called on every group.
      stateEncoder - Encoder for the state type.
      outputEncoder - Encoder for the output type.
      timeoutConf - Timeout configuration for groups that do not receive data for a while.

      See Encoder for more details on what types are encodable to Spark SQL.

      Returns:
      (undocumented)
      Since:
      2.2.0

    • mapGroupsWithState

      public <S, U> Dataset<U> mapGroupsWithState(MapGroupsWithStateFunction<K,V,S,U> func, Encoder<S> stateEncoder, Encoder<U> outputEncoder, GroupStateTimeout timeoutConf, KeyValueGroupedDataset<K,S> initialState)
      (Java-specific) Applies the given function to each group of data, while maintaining a user-defined per-group state. The result Dataset will represent the objects returned by the function. For a static batch Dataset, the function will be invoked once per group. For a streaming Dataset, the function will be invoked for each group repeatedly in every trigger, and updates to each group's state will be saved across invocations. See GroupState for more details.

      Parameters:
      func - Function to be called on every group.
      stateEncoder - Encoder for the state type.
      outputEncoder - Encoder for the output type.
      timeoutConf - Timeout configuration for groups that do not receive data for a while.
      initialState - The user provided state that will be initialized when the first batch of data is processed in the streaming query. The user defined function will be called on the state data even if there are no other values in the group.

      See Encoder for more details on what types are encodable to Spark SQL.

      Returns:
      (undocumented)
      Since:
      3.2.0

    • mapValues

      public <W> KeyValueGroupedDataset<K,W> mapValues(scala.Function1<V,W> func, Encoder<W> evidence$2)
      Returns a new KeyValueGroupedDataset where the given function func has been applied to the data. The grouping key is unchanged by this. 

      
   // Create values grouped by key from a Dataset[(K, V)]
   ds.groupByKey(_._1).mapValues(_._2) // Scala

      Parameters:
      func - (undocumented)
      evidence$2 - (undocumented)
      Returns:
      (undocumented)
      Since:
      2.1.0

    • mapValues

      public <W> KeyValueGroupedDataset<K,W> mapValues(MapFunction<V,W> func, Encoder<W> encoder)
      Returns a new KeyValueGroupedDataset where the given function func has been applied to the data. The grouping key is unchanged by this. 

      
   // Create Integer values grouped by String key from a Dataset<Tuple2<String, Integer>>
   Dataset<Tuple2<String, Integer>> ds = ...;
   KeyValueGroupedDataset<String, Integer> grouped =
     ds.groupByKey(t -> t._1, Encoders.STRING()).mapValues(t -> t._2, Encoders.INT());

      Parameters:
      func - (undocumented)
      encoder - (undocumented)
      Returns:
      (undocumented)
      Since:
      2.1.0

    • queryExecution

      public org.apache.spark.sql.execution.QueryExecution queryExecution()

    • reduceGroups

      public Dataset<scala.Tuple2<K,V>> reduceGroups(scala.Function2<V,V,V> f)
      (Scala-specific) Reduces the elements of each group of data using the specified binary function. The given function must be commutative and associative or the result may be non-deterministic.

      Parameters:
      f - (undocumented)
      Returns:
      (undocumented)
      Since:
      1.6.0

    • reduceGroups

      public Dataset<scala.Tuple2<K,V>> reduceGroups(ReduceFunction<V> f)
      (Java-specific) Reduces the elements of each group of data using the specified binary function. The given function must be commutative and associative or the result may be non-deterministic.

      Parameters:
      f - (undocumented)
      Returns:
      (undocumented)
      Since:
      1.6.0

    • toString

      public String toString()
      Overrides:
      toString in class Object