2010YOUY01 commented on issue #22854: URL: https://github.com/apache/datafusion/issues/22854#issuecomment-4665514510
> We could go further and specialize the hash table for semijoins I think the best way to implement it is specializing the entire execution stream, not only the hash table. This may actually make both (semi anti OR others) implementations simpler. Semi/anti joins have some subtle behavioral differences from inner/outer joins. If we try to reuse the same control flow/state machine, we'll likely end up with internal flags controlling different execution paths, making the code harder to reason about and extend. @mbutrovich used a separate-streams approach when optimizing semi/anti joins in SMJ, which seems related to the same concern: - https://github.com/apache/datafusion/pull/20806 -- 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]
