Re: Add pg_stat_kind_info system view

On Mon, Aug 03, 2026 at 04:51:56PM -0500, Sami Imseih wrote:
> Where this may become questionable is because there is slightly more
> locking overhead if we go with the registry approach. The registry path goes
> through more locking during backend startup (attaching to the
> registry's own DSA,
> looking up the entry, then attaching to the pgstat DSA) compared to the
> current code which does a single dsa_attach_in_place at a known address.
> With a high connection churn benchmark, using -C
>
> ```
> pgbench -C -c $clients -T 10 -n -f bench.sql
> ```
>
> 35-40 microseconds, but this is an extreme case of high connection churn.

I am not troubled by these numbers myself; that's barely noticeable.
But I have to admit that some folks around here would likely complain
if we change that, so I would live the optimization in place, and just
give up on the idea. Sad, but well, I like the concept of a peaceful
life if I can.

Saying that. Do you think that there could be a path forward where we
could optimize the registry locking, benefiting everybody who uses
this API? Just trying to think about all the sides of the coin.
--
Michael