Hi everyone, I just opened a PR to add an `unregister` endpoint to the REST spec, #16400 <https://github.com/apache/iceberg/pull/16400>. Unregister is the opposite of `register` and allows you to remove a table from a catalog without deleting its underlying data and metadata files. The purpose is to allow moving from one catalog to another.
I think it was just an oversight that we didn't already have this. I know that we've talked about adding a way to unregister a table in the past, but I didn't see a previous email thread so I thought I'd start this one. We originally assumed that the drop table endpoint would work, but we need a different one for two reasons. First, most REST catalogs take care of table cleanup (rather than putting the responsibility on the user or engine at the time DROP is run) and we need a way to prevent files from being removed. Second, DROP doesn't work for concurrent operations. We need to return the current table state and metadata location from the `unregister` operation and have the assurance that it is the latest state from the catalog and that any other operations against the table will fail. Please take a look and reply. If there aren't many objections, I'll try to start a vote thread sometime this week. Thanks, Ryan
