apache/spark — pull request #2412 by staple (2014-09-16 15:36:01+00:00)
Title: [SPARK-3550][MLLIB] Disable automatic rdd caching for relevant learners.

The NaiveBayes, ALS, and DecisionTree learners do not require external caching to prevent repeated RDD re-evaluation during learning iterations. NaiveBayes only evaluates its input RDD once, while ALS and DecisionTree internally persist transformations of their input RDDs.