zsxwing commented on a change in pull request #25407: [SPARK-28650][SS][DOC] Correct explanation of guarantee for ForeachWriter URL: https://github.com/apache/spark/pull/25407#discussion_r315442383
########## File path: sql/core/src/main/scala/org/apache/spark/sql/ForeachWriter.scala ########## @@ -50,14 +50,10 @@ import org.apache.spark.annotation.Evolving * * Important points to note: * <ul> - * <li>The `partitionId` and `epochId` can be used to deduplicate generated data when failures - * cause reprocessing of some input data. This depends on the execution mode of the query. If - * the streaming query is being executed in the micro-batch mode, then every partition - * represented by a unique tuple (partitionId, epochId) is guaranteed to have the same data. - * Hence, (partitionId, epochId) can be used to deduplicate and/or transactionally commit data - * and achieve exactly-once guarantees. However, if the streaming query is being executed in the - * continuous mode, then this guarantee does not hold and therefore should not be used for - * deduplication. + * <li>Spark doesn't guarantee same output for (partitionId, epochId) on failure, so deduplication Review comment: ditto ---------------------------------------------------------------- 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
