trait JavaRDDLike[T, This <: JavaRDDLike[T, This]] extends Serializable
Defines operations common to several Java RDD implementations.
- Note
This trait is not intended to be implemented by user code.
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final
def
!=(arg0: Any): Boolean
- Definition Classes
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final
def
##(): Int
- Definition Classes
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final
def
==(arg0: Any): Boolean
- Definition Classes
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-
def
aggregate[U](zeroValue: U)(seqOp: Function2[U, T, U], combOp: Function2[U, U, U]): U
Aggregate the elements of each partition, and then the results for all the partitions, using given combine functions and a neutral "zero value".
Aggregate the elements of each partition, and then the results for all the partitions, using given combine functions and a neutral "zero value". This function can return a different result type, U, than the type of this RDD, T. Thus, we need one operation for merging a T into an U and one operation for merging two U's, as in scala.TraversableOnce. Both of these functions are allowed to modify and return their first argument instead of creating a new U to avoid memory allocation.
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final
def
asInstanceOf[T0]: T0
- Definition Classes
- Any
-
def
cartesian[U](other: JavaRDDLike[U, _]): JavaPairRDD[T, U]
Return the Cartesian product of this RDD and another one, that is, the RDD of all pairs of elements (a, b) where a is in
this
and b is inother
. -
def
checkpoint(): Unit
Mark this RDD for checkpointing.
Mark this RDD for checkpointing. It will be saved to a file inside the checkpoint directory set with SparkContext.setCheckpointDir() and all references to its parent RDDs will be removed. This function must be called before any job has been executed on this RDD. It is strongly recommended that this RDD is persisted in memory, otherwise saving it on a file will require recomputation.
-
def
clone(): AnyRef
- Attributes
- protected[lang]
- Definition Classes
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- Annotations
- @throws( ... ) @native()
-
def
collect(): List[T]
Return an array that contains all of the elements in this RDD.
Return an array that contains all of the elements in this RDD.
- Note
this method should only be used if the resulting array is expected to be small, as all the data is loaded into the driver's memory.
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def
collectAsync(): JavaFutureAction[List[T]]
The asynchronous version of
collect
, which returns a future for retrieving an array containing all of the elements in this RDD.The asynchronous version of
collect
, which returns a future for retrieving an array containing all of the elements in this RDD.- Note
this method should only be used if the resulting array is expected to be small, as all the data is loaded into the driver's memory.
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def
collectPartitions(partitionIds: Array[Int]): Array[List[T]]
Return an array that contains all of the elements in a specific partition of this RDD.
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def
context: SparkContext
The org.apache.spark.SparkContext that this RDD was created on.
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def
count(): Long
Return the number of elements in the RDD.
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def
countApprox(timeout: Long): PartialResult[BoundedDouble]
Approximate version of count() that returns a potentially incomplete result within a timeout, even if not all tasks have finished.
Approximate version of count() that returns a potentially incomplete result within a timeout, even if not all tasks have finished.
- timeout
maximum time to wait for the job, in milliseconds
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def
countApprox(timeout: Long, confidence: Double): PartialResult[BoundedDouble]
Approximate version of count() that returns a potentially incomplete result within a timeout, even if not all tasks have finished.
Approximate version of count() that returns a potentially incomplete result within a timeout, even if not all tasks have finished.
The confidence is the probability that the error bounds of the result will contain the true value. That is, if countApprox were called repeatedly with confidence 0.9, we would expect 90% of the results to contain the true count. The confidence must be in the range [0,1] or an exception will be thrown.
- timeout
maximum time to wait for the job, in milliseconds
- confidence
the desired statistical confidence in the result
- returns
a potentially incomplete result, with error bounds
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def
countApproxDistinct(relativeSD: Double): Long
Return approximate number of distinct elements in the RDD.
Return approximate number of distinct elements in the RDD.
The algorithm used is based on streamlib's implementation of "HyperLogLog in Practice: Algorithmic Engineering of a State of The Art Cardinality Estimation Algorithm", available here.
- relativeSD
Relative accuracy. Smaller values create counters that require more space. It must be greater than 0.000017.
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def
countAsync(): JavaFutureAction[Long]
The asynchronous version of
count
, which returns a future for counting the number of elements in this RDD. -
def
countByValue(): Map[T, Long]
Return the count of each unique value in this RDD as a map of (value, count) pairs.
Return the count of each unique value in this RDD as a map of (value, count) pairs. The final combine step happens locally on the master, equivalent to running a single reduce task.
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def
countByValueApprox(timeout: Long): PartialResult[Map[T, BoundedDouble]]
Approximate version of countByValue().
Approximate version of countByValue().
- timeout
maximum time to wait for the job, in milliseconds
- returns
a potentially incomplete result, with error bounds
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def
countByValueApprox(timeout: Long, confidence: Double): PartialResult[Map[T, BoundedDouble]]
Approximate version of countByValue().
Approximate version of countByValue().
The confidence is the probability that the error bounds of the result will contain the true value. That is, if countApprox were called repeatedly with confidence 0.9, we would expect 90% of the results to contain the true count. The confidence must be in the range [0,1] or an exception will be thrown.
- timeout
maximum time to wait for the job, in milliseconds
- confidence
the desired statistical confidence in the result
- returns
a potentially incomplete result, with error bounds
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final
def
eq(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
-
def
equals(arg0: Any): Boolean
- Definition Classes
- AnyRef → Any
-
def
finalize(): Unit
- Attributes
- protected[lang]
- Definition Classes
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- Annotations
- @throws( classOf[java.lang.Throwable] )
-
def
first(): T
Return the first element in this RDD.
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def
flatMap[U](f: FlatMapFunction[T, U]): JavaRDD[U]
Return a new RDD by first applying a function to all elements of this RDD, and then flattening the results.
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def
flatMapToDouble(f: DoubleFlatMapFunction[T]): JavaDoubleRDD
Return a new RDD by first applying a function to all elements of this RDD, and then flattening the results.
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def
flatMapToPair[K2, V2](f: PairFlatMapFunction[T, K2, V2]): JavaPairRDD[K2, V2]
Return a new RDD by first applying a function to all elements of this RDD, and then flattening the results.
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def
fold(zeroValue: T)(f: Function2[T, T, T]): T
Aggregate the elements of each partition, and then the results for all the partitions, using a given associative function and a neutral "zero value".
Aggregate the elements of each partition, and then the results for all the partitions, using a given associative function and a neutral "zero value". The function op(t1, t2) is allowed to modify t1 and return it as its result value to avoid object allocation; however, it should not modify t2.
This behaves somewhat differently from fold operations implemented for non-distributed collections in functional languages like Scala. This fold operation may be applied to partitions individually, and then fold those results into the final result, rather than apply the fold to each element sequentially in some defined ordering. For functions that are not commutative, the result may differ from that of a fold applied to a non-distributed collection.
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def
foreach(f: VoidFunction[T]): Unit
Applies a function f to all elements of this RDD.
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def
foreachAsync(f: VoidFunction[T]): JavaFutureAction[Void]
The asynchronous version of the
foreach
action, which applies a function f to all the elements of this RDD. -
def
foreachPartition(f: VoidFunction[Iterator[T]]): Unit
Applies a function f to each partition of this RDD.
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def
foreachPartitionAsync(f: VoidFunction[Iterator[T]]): JavaFutureAction[Void]
The asynchronous version of the
foreachPartition
action, which applies a function f to each partition of this RDD. -
def
getCheckpointFile(): Optional[String]
Gets the name of the file to which this RDD was checkpointed
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final
def
getClass(): Class[_]
- Definition Classes
- AnyRef → Any
- Annotations
- @native()
-
def
getNumPartitions: Int
Return the number of partitions in this RDD.
Return the number of partitions in this RDD.
- Annotations
- @Since( "1.6.0" )
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def
getStorageLevel: StorageLevel
Get the RDD's current storage level, or StorageLevel.NONE if none is set.
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def
glom(): JavaRDD[List[T]]
Return an RDD created by coalescing all elements within each partition into an array.
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def
groupBy[U](f: Function[T, U], numPartitions: Int): JavaPairRDD[U, Iterable[T]]
Return an RDD of grouped elements.
Return an RDD of grouped elements. Each group consists of a key and a sequence of elements mapping to that key.
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def
groupBy[U](f: Function[T, U]): JavaPairRDD[U, Iterable[T]]
Return an RDD of grouped elements.
Return an RDD of grouped elements. Each group consists of a key and a sequence of elements mapping to that key.
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def
hashCode(): Int
- Definition Classes
- AnyRef → Any
- Annotations
- @native()
-
def
id: Int
A unique ID for this RDD (within its SparkContext).
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def
isCheckpointed: Boolean
Return whether this RDD has been checkpointed or not
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def
isEmpty(): Boolean
- returns
true if and only if the RDD contains no elements at all. Note that an RDD may be empty even when it has at least 1 partition.
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final
def
isInstanceOf[T0]: Boolean
- Definition Classes
- Any
-
def
iterator(split: Partition, taskContext: TaskContext): Iterator[T]
Internal method to this RDD; will read from cache if applicable, or otherwise compute it.
Internal method to this RDD; will read from cache if applicable, or otherwise compute it. This should not be called by users directly, but is available for implementers of custom subclasses of RDD.
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def
keyBy[U](f: Function[T, U]): JavaPairRDD[U, T]
Creates tuples of the elements in this RDD by applying
f
. -
def
map[R](f: Function[T, R]): JavaRDD[R]
Return a new RDD by applying a function to all elements of this RDD.
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def
mapPartitions[U](f: FlatMapFunction[Iterator[T], U], preservesPartitioning: Boolean): JavaRDD[U]
Return a new RDD by applying a function to each partition of this RDD.
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def
mapPartitions[U](f: FlatMapFunction[Iterator[T], U]): JavaRDD[U]
Return a new RDD by applying a function to each partition of this RDD.
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def
mapPartitionsToDouble(f: DoubleFlatMapFunction[Iterator[T]], preservesPartitioning: Boolean): JavaDoubleRDD
Return a new RDD by applying a function to each partition of this RDD.
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def
mapPartitionsToDouble(f: DoubleFlatMapFunction[Iterator[T]]): JavaDoubleRDD
Return a new RDD by applying a function to each partition of this RDD.
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def
mapPartitionsToPair[K2, V2](f: PairFlatMapFunction[Iterator[T], K2, V2], preservesPartitioning: Boolean): JavaPairRDD[K2, V2]
Return a new RDD by applying a function to each partition of this RDD.
-
def
mapPartitionsToPair[K2, V2](f: PairFlatMapFunction[Iterator[T], K2, V2]): JavaPairRDD[K2, V2]
Return a new RDD by applying a function to each partition of this RDD.
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def
mapPartitionsWithIndex[R](f: Function2[Integer, Iterator[T], Iterator[R]], preservesPartitioning: Boolean = false): JavaRDD[R]
Return a new RDD by applying a function to each partition of this RDD, while tracking the index of the original partition.
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def
mapToDouble[R](f: DoubleFunction[T]): JavaDoubleRDD
Return a new RDD by applying a function to all elements of this RDD.
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def
mapToPair[K2, V2](f: PairFunction[T, K2, V2]): JavaPairRDD[K2, V2]
Return a new RDD by applying a function to all elements of this RDD.
-
def
max(comp: Comparator[T]): T
Returns the maximum element from this RDD as defined by the specified Comparator[T].
Returns the maximum element from this RDD as defined by the specified Comparator[T].
- comp
the comparator that defines ordering
- returns
the maximum of the RDD
-
def
min(comp: Comparator[T]): T
Returns the minimum element from this RDD as defined by the specified Comparator[T].
Returns the minimum element from this RDD as defined by the specified Comparator[T].
- comp
the comparator that defines ordering
- returns
the minimum of the RDD
- def name(): String
-
final
def
ne(arg0: AnyRef): Boolean
- Definition Classes
- AnyRef
-
final
def
notify(): Unit
- Definition Classes
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- Annotations
- @native()
-
final
def
notifyAll(): Unit
- Definition Classes
- AnyRef
- Annotations
- @native()
-
def
partitioner: Optional[Partitioner]
The partitioner of this RDD.
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def
partitions: List[Partition]
Set of partitions in this RDD.
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def
pipe(command: List[String], env: Map[String, String], separateWorkingDir: Boolean, bufferSize: Int, encoding: String): JavaRDD[String]
Return an RDD created by piping elements to a forked external process.
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def
pipe(command: List[String], env: Map[String, String], separateWorkingDir: Boolean, bufferSize: Int): JavaRDD[String]
Return an RDD created by piping elements to a forked external process.
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def
pipe(command: List[String], env: Map[String, String]): JavaRDD[String]
Return an RDD created by piping elements to a forked external process.
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def
pipe(command: List[String]): JavaRDD[String]
Return an RDD created by piping elements to a forked external process.
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def
pipe(command: String): JavaRDD[String]
Return an RDD created by piping elements to a forked external process.
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def
reduce(f: Function2[T, T, T]): T
Reduces the elements of this RDD using the specified commutative and associative binary operator.
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def
saveAsObjectFile(path: String): Unit
Save this RDD as a SequenceFile of serialized objects.
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def
saveAsTextFile(path: String, codec: Class[_ <: CompressionCodec]): Unit
Save this RDD as a compressed text file, using string representations of elements.
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def
saveAsTextFile(path: String): Unit
Save this RDD as a text file, using string representations of elements.
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final
def
synchronized[T0](arg0: ⇒ T0): T0
- Definition Classes
- AnyRef
-
def
take(num: Int): List[T]
Take the first num elements of the RDD.
Take the first num elements of the RDD. This currently scans the partitions *one by one*, so it will be slow if a lot of partitions are required. In that case, use collect() to get the whole RDD instead.
- Note
this method should only be used if the resulting array is expected to be small, as all the data is loaded into the driver's memory.
-
def
takeAsync(num: Int): JavaFutureAction[List[T]]
The asynchronous version of the
take
action, which returns a future for retrieving the firstnum
elements of this RDD.The asynchronous version of the
take
action, which returns a future for retrieving the firstnum
elements of this RDD.- Note
this method should only be used if the resulting array is expected to be small, as all the data is loaded into the driver's memory.
-
def
takeOrdered(num: Int): List[T]
Returns the first k (smallest) elements from this RDD using the natural ordering for T while maintain the order.
Returns the first k (smallest) elements from this RDD using the natural ordering for T while maintain the order.
- num
k, the number of top elements to return
- returns
an array of top elements
- Note
this method should only be used if the resulting array is expected to be small, as all the data is loaded into the driver's memory.
-
def
takeOrdered(num: Int, comp: Comparator[T]): List[T]
Returns the first k (smallest) elements from this RDD as defined by the specified Comparator[T] and maintains the order.
Returns the first k (smallest) elements from this RDD as defined by the specified Comparator[T] and maintains the order.
- num
k, the number of elements to return
- comp
the comparator that defines the order
- returns
an array of top elements
- Note
this method should only be used if the resulting array is expected to be small, as all the data is loaded into the driver's memory.
- def takeSample(withReplacement: Boolean, num: Int, seed: Long): List[T]
- def takeSample(withReplacement: Boolean, num: Int): List[T]
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def
toDebugString(): String
A description of this RDD and its recursive dependencies for debugging.
-
def
toLocalIterator(): Iterator[T]
Return an iterator that contains all of the elements in this RDD.
Return an iterator that contains all of the elements in this RDD.
The iterator will consume as much memory as the largest partition in this RDD.
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def
toString(): String
- Definition Classes
- AnyRef → Any
-
def
top(num: Int): List[T]
Returns the top k (largest) elements from this RDD using the natural ordering for T and maintains the order.
Returns the top k (largest) elements from this RDD using the natural ordering for T and maintains the order.
- num
k, the number of top elements to return
- returns
an array of top elements
- Note
this method should only be used if the resulting array is expected to be small, as all the data is loaded into the driver's memory.
-
def
top(num: Int, comp: Comparator[T]): List[T]
Returns the top k (largest) elements from this RDD as defined by the specified Comparator[T] and maintains the order.
Returns the top k (largest) elements from this RDD as defined by the specified Comparator[T] and maintains the order.
- num
k, the number of top elements to return
- comp
the comparator that defines the order
- returns
an array of top elements
- Note
this method should only be used if the resulting array is expected to be small, as all the data is loaded into the driver's memory.
-
def
treeAggregate[U](zeroValue: U, seqOp: Function2[U, T, U], combOp: Function2[U, U, U], depth: Int, finalAggregateOnExecutor: Boolean): U
org.apache.spark.api.java.JavaRDDLike.treeAggregate
with a parameter to do the final aggregation on the executor. -
def
treeAggregate[U](zeroValue: U, seqOp: Function2[U, T, U], combOp: Function2[U, U, U]): U
org.apache.spark.api.java.JavaRDDLike.treeAggregate
with suggested depth 2. -
def
treeAggregate[U](zeroValue: U, seqOp: Function2[U, T, U], combOp: Function2[U, U, U], depth: Int): U
Aggregates the elements of this RDD in a multi-level tree pattern.
Aggregates the elements of this RDD in a multi-level tree pattern.
- depth
suggested depth of the tree
-
def
treeReduce(f: Function2[T, T, T]): T
org.apache.spark.api.java.JavaRDDLike.treeReduce
with suggested depth 2. -
def
treeReduce(f: Function2[T, T, T], depth: Int): T
Reduces the elements of this RDD in a multi-level tree pattern.
Reduces the elements of this RDD in a multi-level tree pattern.
- depth
suggested depth of the tree
-
final
def
wait(): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
-
final
def
wait(arg0: Long, arg1: Int): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... )
-
final
def
wait(arg0: Long): Unit
- Definition Classes
- AnyRef
- Annotations
- @throws( ... ) @native()
-
def
zip[U](other: JavaRDDLike[U, _]): JavaPairRDD[T, U]
Zips this RDD with another one, returning key-value pairs with the first element in each RDD, second element in each RDD, etc.
Zips this RDD with another one, returning key-value pairs with the first element in each RDD, second element in each RDD, etc. Assumes that the two RDDs have the *same number of partitions* and the *same number of elements in each partition* (e.g. one was made through a map on the other).
-
def
zipPartitions[U, V](other: JavaRDDLike[U, _], f: FlatMapFunction2[Iterator[T], Iterator[U], V]): JavaRDD[V]
Zip this RDD's partitions with one (or more) RDD(s) and return a new RDD by applying a function to the zipped partitions.
Zip this RDD's partitions with one (or more) RDD(s) and return a new RDD by applying a function to the zipped partitions. Assumes that all the RDDs have the *same number of partitions*, but does *not* require them to have the same number of elements in each partition.
-
def
zipWithIndex(): JavaPairRDD[T, Long]
Zips this RDD with its element indices.
Zips this RDD with its element indices. The ordering is first based on the partition index and then the ordering of items within each partition. So the first item in the first partition gets index 0, and the last item in the last partition receives the largest index. This is similar to Scala's zipWithIndex but it uses Long instead of Int as the index type. This method needs to trigger a spark job when this RDD contains more than one partitions.
-
def
zipWithUniqueId(): JavaPairRDD[T, Long]
Zips this RDD with generated unique Long ids.
Zips this RDD with generated unique Long ids. Items in the kth partition will get ids k, n+k, 2*n+k, ..., where n is the number of partitions. So there may exist gaps, but this method won't trigger a spark job, which is different from org.apache.spark.rdd.RDD#zipWithIndex.