Transformations on CompactBuffer in spark

Question

Lets say I have a pair RDD as follows:

(John,10)
(John,9)
(Rachel,5)
(Rachel,6)
(Rachel,8)

Now if I run groupByKey( ) we get the following result

(John,CompactBuffer(10,9)) 
(Rachel,CompactBuffer(5,6,8))

How do I transform this to a pair RDD of String,(Int,Int) as follows

(John,(19,2))   { 1st entry is sum and 2nd entry is count }
(Rachel,(19,3))

I know this can be possible with other methods without groupByKey but I want to know how to work with groupByKey and CompactBuffer

Answer 1

Treat CompactBuffer as normal ArrayBuffer

On result rdd after groupByKey use aggregate .agg(sum("value") as "valueSum",count())

Refer Stackoverflow question about CompactBuffer