xiedeyantu commented on PR #4447: URL: https://github.com/apache/calcite/pull/4447#issuecomment-3017730409
> Frankly, I think this rule isn't general enough. For systems that support Full Join, this rule usually wouldn't apply. However, for those that don't (like MySQL), users would want a rule (FullJoinRemoveRule) to remove all Full Joins to ensure query correctness. But I don't think this rule would effectively achieve that. > > Can we use MINUS to accomplish? > > > (A ⟕ B) ∪ ((A ⟖ B) − (A ⋈ B)) //union all @suibianwanwank I think that systems that support full join should not use this rule. Systems that do not support full join can use it. But as you said, the current rule is quite limited. I think the MINUS you mentioned is a very good idea, and I plan to try it. -- 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]
