wForget commented on PR #41609: URL: https://github.com/apache/spark/pull/41609#issuecomment-1619894072
> I think it makes sense to optimize skew with broadcast hash join. But it seems still useful when localShuffleReaderEnabled is enabled. Here is an attempt to resolve skewed partition with local shuffle reader, #40312. I tried the test case in #40312. The optimized plan of OptimizeShuffleWithLocalRead is rolled back because there is a HashAggregate operation after BroadcastHashJoin which makes ValidateRequirements.validate fail. The implementation of #40312 uses `OptimizeShuffleWithLocalRead.getPartitionSpecs` and `spark.sql.adaptive.forceOptimizeSkewedJoin=true` to make local shuffle read effective, but it will introduce additional shuffle, which seems not a good way. How about we remove the localShuffleReaderEnabled judgment in the current implementation? -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
