On Thu, Jan 24, 2019 at 9:01 AM twoflower <standa.ku...@gmail.com> wrote:
> Yes! That was it, after running VACUUM TABLE history_translation, the > query is now executed using index-only scan. > > I was under the impression that ANALYZE TABLE history_translation is > enough, but it is not. > Only a VACUUM will update the visibility map. https://www.postgresql.org/docs/current/storage-vm.html I used to think the same, that ANALYZE was enough, coming from an Oracle background. I learned later that the visibility map isn't just used to determine what to vacuum, but it is used by the optimizer/planner when evaluating execution plans. -- Don Seiler www.seiler.us