cloud-fan commented on issue #27327: Revert "[SPARK-30535][SQL] Migrate ALTER TABLE commands to the new framework URL: https://github.com/apache/spark/pull/27327#issuecomment-577479780 1. I think it's pretty natural to have the table as a child of the command. We can't do it before as all tables must be resolved to v2 relation and we may have rules to catch v2 relation to do scan related optimization and break the commands. Now we have dedicated table plans for commands (`ResolvedTable`, `ResolvedView`, etc.) 2. I don't think we can differentiate Hive based Alter table CHANGE COLUMN and ALTER COLUMN syntax. Even if revert this commit, we still create the same statement plan for these 2 syntaxes. 3. Normalizing columns is a valid concern. It's easier to do normalization if we have a single logical plan for all ALTER TABLE commands. We can bring back the statement plans, or create AlterTable in the parser directly. In general I don't think the original PR has a serious problem. But ALTER TABLE is a very important command and I'm fine to revert if we don't have enough confidence in it.
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