Re: (docs): add missing info about ShareLocks

On Sat, 2025-11-22 at 09:07 +0100, Alpha Shuro wrote:
> I had a production incident a few weeks ago while using deferred indexes, where
> the Postgres docs lead me down the wrong path of investigation due to missing details.
> Specifically, the docs implied that a `ShareLock` was only acquired when creating
> indexes, but only after looking at the code did I learn that this lock is also
> acquired when transactions are waiting for other transactions to complete.
> I think this would be helpful to someone who might find themselves on the same path
> in the future, and as I understand it this mailing list is the way to submit patches
> to the docs?

No, that is wrong. This section is about table locks, and a lock on a transaction ID
should, if anywhere, be documented elsewhere. Actually, there is already something
about transaction ID locks in https://www.postgresql.org/docs/current/xact-locking.html

Perhaps you could improve that short documentation?

Yours,
Laurenz Albe

PS: There are also SHARE locks on rows.