andygrove commented on issue #6484: URL: https://github.com/apache/datafusion-comet/issues/6484#issuecomment-5934200196
Native semi and anti joins have the same walk today. With `BuildRight` they become `RightSemi` and `RightAnti`, which go through the same `lookup_join_hashmap` and only collapse duplicates afterwards in `adjust_indices_by_join_type`. In a debug build on 09-25, with 200k probe rows and 2,000 of them matching one key, repeating that key 20k times on the build side took the semi join to 242 ms and the existence join to 371 ms. Spark stayed at 50 to 65 ms. Spark answers all three with a single lookup when there is no condition, and its `ShuffledHashJoinExec` drops duplicate build keys for them (`ignoreDuplicatedKey`). Could we widen this issue to cover semi and anti joins too, so one fix lands for all three? -- 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]
