title: Restart streaming query without stopping application
body: <p>Im trying to restart streaming query in spark using below code inplace of query.awaitTermination(),below code will be inside an infinite loop and looks for trigger to restart query and then executes below code.Basically im trying to refresh cached df.</p>
  
  <pre><code> query.processAllavaialble()
      query.stop()
     //oldDF is a cached Dataframe created from GlobalTempView which is of size 150GB.
            oldDF.unpersist()
      val inputDf: DataFrame = readFile(spec, sparkSession) //read file from S3
      or anyother source
      val recreateddf = inputDf.persist()
      //Start the query// here should i start query again by invoking readStream ?
  </code></pre>
  
  <p>But when i looked into spark documentation it says</p>
  
  <pre><code>void processAllAvailable() ///documentation says This method is intended for testing/// Blocks until all available data in the source has been processed and committed to the sink. This method is intended for testing. Note that in the case of continually arriving data, this method may block forever. Additionally, this method is only guaranteed to block until data that has been synchronously appended data to a Source prior to invocation. (i.e. getOffset must immediately reflect the addition).
  
  
  stop() Stops the execution of this query if it is running. This method blocks until the threads performing execution has stopped.
  </code></pre>
  
  <p>So whats the better way to restart query without stopping my spark streaming application</p>