Dandandan opened a new issue, #18939: URL: https://github.com/apache/datafusion/issues/18939
### Is your feature request related to a problem or challenge? Hash Joins with large build side & lots of hash-duplicates are relatively slow in DataFusion. The cost seems largely associated with traversing the chain of duplicates (`chain_traverse`) (1) + which is known to be very cache-inefficient, as the access pattern is mostly random. Currently, we implement hash joins partitioned by hash, but we can implement a more efficient algorithm (radix hash join) [TODO: collect some issues / examples] (1) https://github.com/apache/datafusion/issues/17494 ### Describe the solution you'd like Implement a version of Radix Hash Joins: <img width="413" height="282" alt="Image" src="https://github.com/user-attachments/assets/14db8f23-a386-4e12-8b16-57ebe9823cad"; /> https://15721.courses.cs.cmu.edu/spring2016/papers/balkesen-icde2013.pdf ### Describe alternatives you've considered _No response_ ### Additional context _No response_ -- 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]
