Self Learning Apache Spark Online

[trendzman]

Hello All. I am new to this forum.

I need some inputs from expertise from the DB, on how to learn Spark by my own. On some research i learnt that Scala and Python are primary languages which are used with Spark. But now sure where to start with. If i start learning Scala/Python, not sure how much knowledge should i require for start learning Spark. Recently started having hands-on experience in Hadoop(File System, Sqoop, Pig) in my leisure time.  But  want to aggressively invest some time moving to other technology.I am currently working as Oracle Developer since long time, and i am very desperate on switching to Big Data path.

Please advice.