n3nash commented on issue #3078: URL: https://github.com/apache/hudi/issues/3078#issuecomment-862008843
@tandonraghav To expect the payload semantics for compaction, you need to override the `preCombine` implementation and have the same implementation across `combineAndGetUpdateValue` and `preCombine`. The idea is that whether it is 2 records in memory, 2 records on disk or 1 record in memory vs 1 on disk -> we call either `preCombine` or `combineAndGetUpdateValue` depending on what can be constructed as a payload. Please try overriding preCombine and let me know if you still see problems. We might open a documentation around this to make it more clear. -- 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
