PCollection (Apache Crunch 0.5.0-incubating API)

All Known Subinterfaces:

PGroupedTable<K,V>, PTable<K,V>
```
public interface PCollection<S>
```
A representation of an immutable, distributed collection of elements that is the fundamental target of computations in Crunch.

Method Summary

Methods
Modifier and Type	Method and Description
`PObject<Collection<S>>`	`asCollection()`
`<K> PTable<K,S>`	`by(MapFn<S,K> extractKeyFn, PType<K> keyType)` Apply the given map function to each element of this instance in order to create a `PTable`.
`<K> PTable<K,S>`	`by(String name, MapFn<S,K> extractKeyFn, PType<K> keyType)` Apply the given map function to each element of this instance in order to create a `PTable`.
`PTable<S,Long>`	`count()` Returns a `PTable` instance that contains the counts of each unique element of this PCollection.
`PCollection<S>`	`filter(FilterFn<S> filterFn)` Apply the given filter function to this instance and return the resulting `PCollection`.
`PCollection<S>`	`filter(String name, FilterFn<S> filterFn)` Apply the given filter function to this instance and return the resulting `PCollection`.
`String`	`getName()` Returns a shorthand name for this PCollection.
`Pipeline`	`getPipeline()` Returns the `Pipeline` associated with this PCollection.
`PType<S>`	`getPType()` Returns the `PType` of this `PCollection`.
`long`	`getSize()` Returns the size of the data represented by this `PCollection` in bytes.
`PTypeFamily`	`getTypeFamily()` Returns the `PTypeFamily` of this `PCollection`.
`PObject<Long>`	`length()` Returns the number of elements represented by this `PCollection`.
`Iterable<S>`	`materialize()` Returns a reference to the data set represented by this PCollection that may be used by the client to read the data locally.
`PObject<S>`	`max()` Returns a `PObject` of the maximum element of this instance.
`PObject<S>`	`min()` Returns a `PObject` of the minimum element of this instance.
`<K,V> PTable<K,V>`	`parallelDo(DoFn<S,Pair<K,V>> doFn, PTableType<K,V> type)` Similar to the other `parallelDo` instance, but returns a `PTable` instance instead of a `PCollection`.
`<T> PCollection<T>`	`parallelDo(DoFn<S,T> doFn, PType<T> type)` Applies the given doFn to the elements of this `PCollection` and returns a new `PCollection` that is the output of this processing.
`<K,V> PTable<K,V>`	`parallelDo(String name, DoFn<S,Pair<K,V>> doFn, PTableType<K,V> type)` Similar to the other `parallelDo` instance, but returns a `PTable` instance instead of a `PCollection`.
`<K,V> PTable<K,V>`	`parallelDo(String name, DoFn<S,Pair<K,V>> doFn, PTableType<K,V> type, ParallelDoOptions options)` Similar to the other `parallelDo` instance, but returns a `PTable` instance instead of a `PCollection`.
`<T> PCollection<T>`	`parallelDo(String name, DoFn<S,T> doFn, PType<T> type)` Applies the given doFn to the elements of this `PCollection` and returns a new `PCollection` that is the output of this processing.
`<T> PCollection<T>`	`parallelDo(String name, DoFn<S,T> doFn, PType<T> type, ParallelDoOptions options)` Applies the given doFn to the elements of this `PCollection` and returns a new `PCollection` that is the output of this processing.
`PCollection<S>`	`union(PCollection<S>... collections)` Returns a `PCollection` instance that acts as the union of this `PCollection` and the input `PCollection`s.
`PCollection<S>`	`write(Target target)` Write the contents of this `PCollection` to the given `Target`, using the storage format specified by the target.
`PCollection<S>`	`write(Target target, Target.WriteMode writeMode)` Write the contents of this `PCollection` to the given `Target`, using the given `Target.WriteMode` to handle existing targets.

- Method Detail
  - getPipeline
```
Pipeline getPipeline()
```
    Returns the Pipeline associated with this PCollection.
  - union
```
PCollection<S> union(PCollection<S>... collections)
```
    Returns a PCollection instance that acts as the union of this PCollection and the input PCollections.
  - parallelDo
```
<T> PCollection<T> parallelDo(DoFn<S,T> doFn,
                            PType<T> type)
```
    Applies the given doFn to the elements of this PCollection and returns a new PCollection that is the output of this processing.
    
    Parameters:
    doFn - The DoFn to apply
    type - The PType of the resulting PCollection
    
    Returns:
    a new PCollection
  - parallelDo
```
<T> PCollection<T> parallelDo(String name,
                            DoFn<S,T> doFn,
                            PType<T> type)
```
    Applies the given doFn to the elements of this PCollection and returns a new PCollection that is the output of this processing.
    
    Parameters:
    name - An identifier for this processing step, useful for debugging
    doFn - The DoFn to apply
    type - The PType of the resulting PCollection
    
    Returns:
    a new PCollection
  - parallelDo
```
<T> PCollection<T> parallelDo(String name,
                            DoFn<S,T> doFn,
                            PType<T> type,
                            ParallelDoOptions options)
```
    Applies the given doFn to the elements of this PCollection and returns a new PCollection that is the output of this processing.
    
    Parameters:
    name - An identifier for this processing step, useful for debugging
    doFn - The DoFn to apply
    type - The PType of the resulting PCollection
    options - Optional information that is needed for certain pipeline operations
    
    Returns:
    a new PCollection
  - parallelDo
```
<K,V> PTable<K,V> parallelDo(DoFn<S,Pair<K,V>> doFn,
                           PTableType<K,V> type)
```
    Similar to the other parallelDo instance, but returns a PTable instance instead of a PCollection.
    
    Parameters:
    doFn - The DoFn to apply
    type - The PTableType of the resulting PTable
    
    Returns:
    a new PTable
  - parallelDo
```
<K,V> PTable<K,V> parallelDo(String name,
                           DoFn<S,Pair<K,V>> doFn,
                           PTableType<K,V> type)
```
    Similar to the other parallelDo instance, but returns a PTable instance instead of a PCollection.
    
    Parameters:
    name - An identifier for this processing step
    doFn - The DoFn to apply
    type - The PTableType of the resulting PTable
    
    Returns:
    a new PTable
  - parallelDo
```
<K,V> PTable<K,V> parallelDo(String name,
                           DoFn<S,Pair<K,V>> doFn,
                           PTableType<K,V> type,
                           ParallelDoOptions options)
```
    Similar to the other parallelDo instance, but returns a PTable instance instead of a PCollection.
    
    Parameters:
    name - An identifier for this processing step
    doFn - The DoFn to apply
    type - The PTableType of the resulting PTable
    options - Optional information that is needed for certain pipeline operations
    
    Returns:
    a new PTable
  - write
```
PCollection<S> write(Target target)
```
    Write the contents of this PCollection to the given Target, using the storage format specified by the target.
    
    Parameters:
    target - The target to write to
  - write
```
PCollection<S> write(Target target,
                   Target.WriteMode writeMode)
```
    Write the contents of this PCollection to the given Target, using the given Target.WriteMode to handle existing targets.
    
    Parameters:
    target - The target
    writeMode - The rule for handling existing outputs at the target location
  - materialize
```
Iterable<S> materialize()
```
    Returns a reference to the data set represented by this PCollection that may be used by the client to read the data locally.
  - asCollection
```
PObject<Collection<S>> asCollection()
```
    Returns:
    A PObject encapsulating an in-memory Collection containing the values of this PCollection.
  - getPType
```
PType<S> getPType()
```
    Returns the PType of this PCollection.
  - getTypeFamily
```
PTypeFamily getTypeFamily()
```
    Returns the PTypeFamily of this PCollection.
  - getSize
```
long getSize()
```
    Returns the size of the data represented by this PCollection in bytes.
  - length
```
PObject<Long> length()
```
    Returns the number of elements represented by this PCollection.
    
    Returns:
    An PObject containing the number of elements in this PCollection.
  - getName
```
String getName()
```
    Returns a shorthand name for this PCollection.
  - filter
```
PCollection<S> filter(FilterFn<S> filterFn)
```
    Apply the given filter function to this instance and return the resulting PCollection.
  - filter
```
PCollection<S> filter(String name,
                    FilterFn<S> filterFn)
```
    Apply the given filter function to this instance and return the resulting PCollection.
    
    Parameters:
    name - An identifier for this processing step
    filterFn - The FilterFn to apply
  - by
```
<K> PTable<K,S> by(MapFn<S,K> extractKeyFn,
                 PType<K> keyType)
```
    Apply the given map function to each element of this instance in order to create a PTable.
  - by
```
<K> PTable<K,S> by(String name,
                 MapFn<S,K> extractKeyFn,
                 PType<K> keyType)
```
    Apply the given map function to each element of this instance in order to create a PTable.
    
    Parameters:
    name - An identifier for this processing step
    extractKeyFn - The MapFn to apply
  - count
```
PTable<S,Long> count()
```
    Returns a PTable instance that contains the counts of each unique element of this PCollection.
  - max
```
PObject<S> max()
```
    Returns a PObject of the maximum element of this instance.
  - min
```
PObject<S> min()
```
    Returns a PObject of the minimum element of this instance.

Interface PCollection<S>

Method Summary

Method Detail

getPipeline

union

parallelDo

parallelDo

parallelDo

parallelDo

parallelDo

parallelDo

write

write

materialize

asCollection

getPType

getTypeFamily

getSize

length

getName

filter

filter

by

by

count

max

min