cloud-fan commented on PR #38034: URL: https://github.com/apache/spark/pull/38034#issuecomment-1382041199
I'm a bit hesitant to touch the core `TreeNode` library as these things can be hard to generalize. For example, for output ordering `a + b`, if the project list is `a, a as x, b as y1, b as y2`, we should produce `a + y1, a + y2, x + y2, x + y2`. Note that: 1. sometimes we only want to replace one alias as the original attribute `a` is still in the output 2. We might do some early pruning to avoid exponential growth 3. We can strip some expression from the project list, e.g. `empty2null(a)` -> `a` Are you sure the `multiTransform` can meet all these requirements? Can you give an example about how to use it to implement the algorithm in https://github.com/apache/spark/pull/39556#discussion_r1069575600 ? -- 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]
