Hadoop
It’s an open source framework created by the Apache Software Foundation, the same group that created the Apache HTTP Server. At a very high level, Hadoop is a software framework designed to store and process very large data sets across multiple servers.
http://cloud-dba-journey.blogspot.in/2013/02/how-to-learn-hadoop.html
http://hortonworks.com/blog/best-practices-for-selecting-apache-hadoop-hardware/
http://strataconf.com/stratany2013/public/schedule/detail/30769
ORACLE-LEARN 