title: Fetching all the records for a partitionID in cassandra gives RPC timeout
body: <p>I am using Cassandra 1.2.1, composite key and trying to fetch all the records for a particular partitionID. Following is the schema I'm using:</p>
  
  <ul>
  <li>TimeStamp</li>
  <li>Device ID</li>
  <li>Data Transfer</li>
  <li>Location ID</li>
  <li>Device Owner</li>
  </ul>
  
  <p>The primary Key is a composite key: (TimeStamp, Device ID). Therefore TimeStamp is the Partition key. Each record will be 70-80 bytes.</p>
  
  <p>There are 1000 different TimeStamp, and for each timestamp, there are 500K Device IDs. So there are 500 million records, and I want to fetch all the records for a particular timestamp. Something similar to:</p>
  
  <p>Select * from schema where TimeStamp = '..' </p>
  
  <p>My understanding is that this query should be able to fetch all the records fast, since the relevant rows are all stored in contiguous disk location, which means very few disk seeks will give us the result. The filter is on TimeStamp, which means just one node will be hit with the query. Also, the total amount of data is 500K * 80 bytes ~ 40 MB, which is not an awful lot. However, I'm getting RPC Timeouts when I run this with CQL (3) or Astyanax.</p>
  
  <p>Is my understanding that all the records for a partitionID are in contiguous disk location wrong? What should be the correct way to bulk fetch such a data?</p>