chenkovsky commented on PR #14057: URL: https://github.com/apache/datafusion/pull/14057#issuecomment-2644389349
> > as I previously asked, in your implementation "a system column stops being a system column once it's projected" ? If this is correct, then as you said there's no need to add more UTs. > > I have to call out it seems that this behavior is incompatible with Spark. I know whether follow Spark's standard is another problem. but community should be aware of this. I have to revoke my judgements for #14362 from metadata/system propagation side, because previously judgements are based on the assumption that difference between two approaches is just how to transmit the information, the goal is same. but it seems that it's not true. #14362 has own propagation rules. It's really hard for me to talk about a totally different thing. let's look pros and cons directly. pros of this approach: 1. dataframe api friendly. There's no chance to hurt themself for dataframe api user. 2. Spark compatible. Spark has already been battle tested in many areas, it's design to be compatible with many different data sources and data sinks. So there's fewer unknown problems. -- 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: github-unsubscr...@datafusion.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: github-unsubscr...@datafusion.apache.org For additional commands, e-mail: github-h...@datafusion.apache.org