DISK_ONLY - Stores the RDD partitions only on the disk
MEMORY_ONLY_SER - Stores the RDD as serialized Java objects with a one-byte array per partition
MEMORY_ONLY - Stores the RDD as deserialized Java objects in the JVM. If the RDD is not able to fit in the memory available, some partitions won’t be cached
OFF_HEAP - Works like MEMORY_ONLY_SER but stores the data in off-heap memory
MEMORY_AND_DISK - Stores RDD as deserialized Java objects in the JVM. In case the RDD is not able to fit in the memory, additional partitions are stored on the disk
MEMORY_AND_DISK_SER - Identical to MEMORY_ONLY_SER with the exception of storing partitions not able to fit in the memory to the disk
