java - Performance Impact of RDD to JavaRDD conversion -

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i have code , wan work against javardd instead of rdd i'm doing conversion here. know performance impact of transformation specialy when i'm dealing gbs of data. 

rdd<string> textfile = sc.textfile(filepath, 2); javardd<string> javardd = textfile.tojavardd();

this wide or narrow transformation ? difference between javardd , rdd ?

there's no significant performance penalty - javardd simple wrapper around rdd make calls java code more convenient. holds original rdd ad member, , calls member's method on method invocation, example (from javardd.scala):

def cache(): javardd[t] = wraprdd(rdd.cache())

wraprdd boils down new javardd[t](rdd), performance penalty creating thin java object every method invocation, that's entirely negligible it's not done per element in rdd, once entire object.


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