srowen commented on a change in pull request #26469: [SPARK-29844] Improper unpersist strategy in ml.recommendation.ASL.train URL: https://github.com/apache/spark/pull/26469#discussion_r344747970
########## File path: mllib/src/main/scala/org/apache/spark/ml/recommendation/ALS.scala ########## @@ -1041,13 +1041,13 @@ object ALS extends DefaultParamsReadable[ALS] with Logging { .persist(finalRDDStorageLevel) if (finalRDDStorageLevel != StorageLevel.NONE) { userIdAndFactors.count() - itemIdAndFactors.count() - itemFactors.unpersist() userInBlocks.unpersist() userOutBlocks.unpersist() - itemInBlocks.unpersist() itemOutBlocks.unpersist() blockRatings.unpersist() + itemIdAndFactors.count() Review comment: Yes, but itemFactors depends on the previous user RDDs, including userOutBlocks. I think this is done on purpose. EDIT: Hm OK but it's persisted, so shouldn't matter as long as itemFactors is unpersisted afterwards. This is a bit of an optimization right? just tries to free up more space before persisting the item stuff. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org