CachedDataStream (Flink : Runtime 2.0.0 API)

java.lang.Object
- org.apache.flink.streaming.api.datastream.DataStream<T>
- - org.apache.flink.streaming.api.datastream.CachedDataStream<T>

Type Parameters:

T - The type of the elements in this stream.
```
@PublicEvolving
public class CachedDataStream<T>
extends DataStream<T>
```
CachedDataStream represents a DataStream whose intermediate result will be cached at the first time when it is computed. And the cached intermediate result can be used in later job that using the same CachedDataStream to avoid re-computing the intermediate result.

Nested Class Summary
- Nested classes/interfaces inherited from class org.apache.flink.streaming.api.datastream.DataStream
  DataStream.Collector<T>

Field Summary
- Fields inherited from class org.apache.flink.streaming.api.datastream.DataStream
  environment, transformation

Constructor Summary

Constructors
Constructor	Description
`CachedDataStream(StreamExecutionEnvironment environment, org.apache.flink.api.dag.Transformation<T> transformation)`	Create a new `CachedDataStream` in the given execution environment that wrap the given physical transformation to indicates that the transformation should be cached.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`invalidate()`	Invalidate the cache intermediate result of this DataStream to release the physical resources.

Methods inherited from class org.apache.flink.streaming.api.datastream.DataStream
addSink, assignTimestampsAndWatermarks, broadcast, broadcast, clean, coGroup, collectAsync, collectAsync, connect, connect, countWindowAll, countWindowAll, doTransform, executeAndCollect, executeAndCollect, executeAndCollect, executeAndCollect, filter, flatMap, flatMap, forward, fullWindowPartition, getExecutionConfig, getExecutionEnvironment, getId, getMinResources, getParallelism, getPreferredResources, getTransformation, getType, global, join, keyBy, keyBy, keyBy, map, map, partitionCustom, print, print, printToErr, printToErr, process, process, project, rebalance, rescale, setConnectionType, shuffle, sinkTo, sinkTo, transform, transform, union, windowAll, writeToSocket, writeUsingOutputFormat

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - CachedDataStream
```
public CachedDataStream(StreamExecutionEnvironment environment,
                        org.apache.flink.api.dag.Transformation<T> transformation)
```
    Create a new CachedDataStream in the given execution environment that wrap the given physical transformation to indicates that the transformation should be cached.
    
    Parameters:
    
    environment - The StreamExecutionEnvironment
    
    transformation - The physical transformation whose intermediate result should be cached.
- Method Detail
  - invalidate
```
public void invalidate()
                throws Exception
```
    Invalidate the cache intermediate result of this DataStream to release the physical resources. Users are not required to invoke this method to release physical resources unless they want to. Cache will be recreated if it is used after invalidated.
    
    Throws:
    
    Exception