How to uncache RDD?

Question

I used cache() to cache the data in memory but I realized to see the performance without cached data I need to uncache it to remove data from memory:

rdd.cache();
//doing some computation
...
rdd.uncache()

but I got the error said:

value uncache is not a member of org.apache.spark.rdd.RDD[(Int, Array[Float])]

I don't know how to do the uncache then!

Answer 1

RDD can be uncached using unpersist()

rdd.unpersist() 

source

Answer 2

The uncache function doesn't exist. I think that you were looking for unpersist. Which according to the Spark ScalaDoc mark the RDD as non-persistent, and remove all blocks for it from memory and disk.

Answer 3

If you want to remove all the cached RDDs, use this ::

for ((k,v) <- sc.getPersistentRDDs) {
  v.unpersist()
}