bart-samwel commented on pull request #28836: URL: https://github.com/apache/spark/pull/28836#issuecomment-645877735
> Got the point, may be this is why Teradata add a QUALIFY clause to support direct filter by window function. Yeah, and I'm not saying that it isn't useful in some cases, I'm just saying that it's going to be so rare that it'll confuse people. I asked @hvanhovell who actually used Teradata professionally in the past, and his response was that (a) he used this sometimes and it was useful, and (b) it would confuse the heck out of his colleagues when they encountered it. I think point (b) is the most important thing here -- if people just wrap the query as a subquery and then use WHERE, then everybody can understand it immediately (if they understand window functions, at least). People already have a hard time understanding the difference between WHERE and HAVING. Adding a third and even more obscure option wouldn't help understandability. ---------------------------------------------------------------- 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: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@spark.apache.org For additional commands, e-mail: reviews-h...@spark.apache.org
