Every database upgrade I've run has failed in one of 2 ways. The first kind crashes at 3am, pages somebody, and is fixed by breakfast. The second kind runs clean through every smoke test and returns a slightly different number for 3 weeks until finance asks why the dashboard moved. I'll take the crash every time.

DuckDB 2.0.0 LTS ("Cinnamon Teal") shipped on October 21, 2026, and it can fail both ways. It adds a client-server mode, async I/O for object storage, a VARIANT type, triggers, and a new parser. It also writes a file format older versions can't open, and it changes some SQL behavior in ways that give new answers without raising an error. If DuckDB sits anywhere in your pipelines, you have an upgrade decision to make this month.

My position is that the 2.0 additions are nice, but the upgrade plan is where the engineering happens. The concepts behind that plan are compatibility, rollback, write coordination, and verifying results.…