2010YOUY01 commented on PR #22906: URL: https://github.com/apache/datafusion/pull/22906#issuecomment-4696816626
This PR looks like a very nice solution for the cast pattern. I'm comfortable proceeding with it, but please forgive me for briefly advocating an alternative approach (that I'm to happy to help reviewing or implementing): I believe the fundamental goal here is to enable pruning through nested expressions, and the propagation based approach could be a better long term solution. - https://github.com/apache/datafusion/issues/19487 My concern with the preimage approach is that it requires introducing and maintaining an ever-growing set of reverse-transformation rules. Even with additional rules, there will likely still be cases that cannot be handled. If this becomes a supported pattern, I worry that the long-term maintenance burden could be significant. In contrast, the propagation approach seems both more general and easier to reason about. The key intuition is that it follows a forward-evaluation model, similar to normal expression evaluation, whereas the preimage approach attempts to reverse complex expressions back into a simpler form. In many cases, the latter is inherently more difficult and may require expression-specific logic. -- 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]
