Is undelete the right word here? Is this more like restoring the column? Also, it seems like we should follow the spec wording correctly by default. This means we should throw an exception if the column was required and new data has been written to the table. Restoring the column back as nullable is reasonable but must be explicit user intention (flag or argument).
On Tue, Mar 3, 2026 at 5:27 PM Frank Bertsch <[email protected]> wrote: > Hi all, we have 3 positive reviews on the PR. Any chance a committer could > take a look? > > Thanks, > Frank > > On Wed, Feb 18, 2026 at 10:11 PM Frank Bertsch <[email protected]> > wrote: > >> Hey folks, >> >> I have a (relatively) small change here >> <https://github.com/apache/iceberg/pull/15084> to add the capability to >> undelete columns, and a corresponding Spark function. I was hoping to get >> some feedback from the list on this improvement. >> >> I'll note that the spec specifically says column undeletion is allowed, >> but only for these two situations: "Field deletion cannot be rolled back >> unless the field was nullable or if the current snapshot has not changed". >> The PR I've proposed allows for undeleting of non-nullable columns, but >> forces them to be optional upon rollback. I believe this is a reasonable >> tradeoff. >> >> Looking forward to any feedback on the change. >> Frank >> >
