title: Transformation process in Apache Spark
body: <p>Transformations create new RDD based on the existing RDD. Basically, RDDs are immutable and all transformations in Spark are lazy. Data in RDDs is not processed until an action is performed but without processing the data, how are new RDDs created?? For example, in <code>filter</code> operation how are new RDD created without actually loading the RDDs into memory and processing it?</p>