Обсуждение: Documentation bug at: current/sql-vacuum.html, Notes
Isn't this backwards? > If index cleanup is not performed regularly, performance may suffer, because as the table is modified indexes will accumulatedead tuples and the table itself will accumulate dead line pointers that cannot be removed until index cleanupis completed. Indexes have line pointers, tables have tuples, so it should read: > If index cleanup is not performed regularly, performance may suffer, because as the table is modified indexes will accumulatedead line pointers and the table itself will accumulate dead tuples that cannot be removed until index cleanupis completed.
On Wed, Jul 26, 2023 at 10:39:41AM -0700, Christophe Pettus wrote: > Isn't this backwards? > >> If index cleanup is not performed regularly, performance may suffer, because as the table is modified indexes will accumulatedead tuples and the table itself will accumulate dead line pointers that cannot be removed until index cleanupis completed. > > Indexes have line pointers, tables have tuples, so it should read: > >> If index cleanup is not performed regularly, performance may suffer, because as the table is modified indexes will accumulatedead line pointers and the table itself will accumulate dead tuples that cannot be removed until index cleanupis completed. I believe the current phrasing is correct. VACUUM will be able to reclaim the tuple space in the heap, but the line pointers must remain until their corresponding index tuples are removed. -- Nathan Bossart Amazon Web Services: https://aws.amazon.com
> On Jul 26, 2023, at 10:55, Nathan Bossart <nathandbossart@gmail.com> wrote: > > > I believe the current phrasing is correct. VACUUM will be able to reclaim > the tuple space in the heap, but the line pointers must remain until their > corresponding index tuples are removed. Ah, right, thanks.