Re: Improve LWLock tranche name visibility across backends

> On Fri, Aug 22, 2025 at 03:01:53PM -0500, Sami Imseih wrote:
> > I kept the local array to serve consecutive reads and to avoid having to
> > take a shared lock on shared memory every time GetLWTrancheName is
> > called. A new LWLock to protect this array is required.
>
> I'm not seeing why we need this cache anymore.  This is an append-only
> list, so we could instead keep a backend-local copy of LWLockCounter that
> gets updated as needed.  As long as the ID is less than our backend-local
> counter, we can go straight to the shared array.  If it is greater, we'll
> have to first update our counter, which should be rare and inexpensive.

When we lookup from shared array only, we need to take a shared lock
every lookup. Acquiring that lock is what I am trying to avoid. You
are saying it's not worth optimizing that part, correct?

--
Sami