Re: 2022-06-16 release announcement draft

On Mon, Jun 13, 2022 at 6:15 PM Jonathan S. Katz <jkatz@postgresql.org> wrote:
> > Perhaps it is also worth mentioning that you can use REINDEX without
> > CONCURRENTLY, even before upgrading.
>
> I'm hesitant on giving too many options. We did put out the "warning"
> announcement providing this as an option. I do think that folks who are
> running CIC/RIC are sensitive to locking, and a plain old "REINDEX" may
> be viable except in an emergency.

The locking implications for plain REINDEX are surprising IMV -- and
so I suggest sticking with what you have here.

In many cases using plain REINDEX is not meaningfully different to
taking a full AccessExclusiveLock on the table (we only acquire an AEL
on the index, but in practice that can be a distinction without a
difference). We at least went some way towards making the situation
with REINDEX locking clearer in a doc patch that recently became
commit 8ac700ac.

--
Peter Geoghegan