cloud-fan commented on pull request #28326: URL: https://github.com/apache/spark/pull/28326#issuecomment-619735441
> I'm wondering why Alias has an explicit metadata and hides the actual attribute's metadata Sometimes we have to, for example, `a + b as c`, what should be the metadata of `c`? I think the root cause is we rely on column metadata to store some important information, and we should make column metadata reliable as possible as we can. For example, `a as c`, if users do not specify the metadata of `c` explicitly, it should inherit metadata from `a`. ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
