szlta opened a new pull request #1894: URL: https://github.com/apache/hive/pull/1894
If delete delta caching is turned off, the plain record reader inside DeleteReaderValue allocates a batch with a schema that is equivalent to that of an insert delta. This is unnecessary as the struct part in a delete delta file is always empty. In cases where we have many delete delta files (e.g. due to compaction failures) and a wide table definition (e.g. 200+ cols) this puts a significant amount of memory pressure on the executor, while these empty structures will never be filled or otherwise utilized. I propose we specify an ACID schema with an empty struct part to this record reader to counter this. Options ---------------------------------------------------------------- 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: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
