title: is nested chunks in spring batch possible
body: <p>Hi I am new to spring batch .</p>
  
  <p>I have situation with spring batch like below :</p>
  
  <p>I need to run a batch for all Promotions [ List of Promotions]</p>
  
  <ul>
  <li><p>For Each Promotion I need to prepare dynamic query with promotion attributes and get all the transaction history and compute promotional points to each user </p>
  
  <p>And here the with above dynamic query I wanted to read again from batch  as it returns results minimum of 50 thousand records .</p></li>
  </ul>
  
  <p>below is the process I am expecting, is this is possible in spring batch?</p>
  
  <ul>
  <li>Read Promotions[Reader reads promotions one by one]
  <ul>
  <li>create query and put it on context</li>
  <li>pass it to the next reader
  <ul>
  <li>reader reads transactions one by one</li>
  <li>process transactions and calculate points</li>
  </ul></li>
  <li>processor</li>
  </ul></li>
  </ul>
  
  <p>My problem here is Not able write nested chunks [ one for read promotions and one for reading transactions].</p>
  
  <p>One alternative is :</p>
  
  <p>Partition the job for each Promotion , in this all promotions will run concurrently , But we need to run one after one .</p>
  
  <p>Can any body  suggest any way for this ?</p>