Wow, so bottom line 1. useful for Streaming cause of the nature of the file system. 2. Probably will loose the append nature of HDFS. 3. Retaining data in me

Wow, so bottom line 1. useful for Streaming cause of the nature of the file system. 2. Probably will loose the append nature of HDFS. 3. Retaining data in memory makes it hard to use with any of the hdfs based databases like hbase. So raw map reducers should definately try it...