hvanhovell commented on PR #38793: URL: https://github.com/apache/spark/pull/38793#issuecomment-1327971103
@amaliujia the semantics of `Alias` and the `name` + `expression` are 100% the same. Both are named expressions, and at the end of the day `withColumns` will produce a `Project` using exactly those `Alias` expressions. The replacement/appending semantics of withColumn does not change anything here. Come to thing of it, having metadata here would actually make sense. There is no way we are ever going to change `Alias`, this has been in databases for the last 50+ years. However, let's entertain the idea of us changing `Alias`, you can solve those problems with proper versioning and a breaking change process (we are going to need both at some point in the not so far away future). I am assuming you are changing `Alias` in the connect protocol, in that case such a breaking change probably means you will introduce a new expression. -- 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]
