zhengruifeng commented on code in PR #47328: URL: https://github.com/apache/spark/pull/47328#discussion_r1676692203
########## mllib/src/main/scala/org/apache/spark/ml/r/AFTSurvivalRegressionWrapper.scala: ########## @@ -129,7 +129,9 @@ private[r] object AFTSurvivalRegressionWrapper extends MLReadable[AFTSurvivalReg val rMetadata = ("class" -> instance.getClass.getName) ~ ("features" -> instance.features.toImmutableArraySeq) val rMetadataJson: String = compact(render(rMetadata)) - sc.parallelize(Seq(rMetadataJson), 1).saveAsTextFile(rMetadataPath) + sparkSession.createDataFrame( + Seq(Tuple1(rMetadataJson)) + ).repartition(1).write.text(rMetadataPath) Review Comment: No, the single partition is needed to avoid creating empty files, even though there is only one row: ``` spark.range(1).select(sf.lit("123")).write.text("/tmp/test-test") ``` ``` (base) ➜ runtime git:(master) ls /tmp/test-test _SUCCESS part-00011-e548682e-21a5-41ea-93bc-0089efccbf4f-c000.txt part-00000-e548682e-21a5-41ea-93bc-0089efccbf4f-c000.txt (base) ➜ runtime git:(master) wc -l /tmp/test-test/* 0 /tmp/test-test/_SUCCESS 0 /tmp/test-test/part-00000-e548682e-21a5-41ea-93bc-0089efccbf4f-c000.txt 1 /tmp/test-test/part-00011-e548682e-21a5-41ea-93bc-0089efccbf4f-c000.txt 1 total ``` I think we can use `coalesce(1)` to avoid this small shuffle -- 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. To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org