Re: PgStat_HashKey padding issue when passed by reference

> On Mon, Sep 08, 2025 at 09:36:52PM -0500, Sami Imseih wrote:
> > But my concern is the flexibility of this approach. If someone is to add an
> > OID field next, they will not be able to as that will be introducing
> > padding.  On the other hand, passing the key by reference and
> > documenting the reason in pgstat_shmem.c will not lose this
> > flexibility.
>
> I don't mind discarding the static assertion idea, but at the end what
> counts for me here is that I don't want to sacrifice future changes in
> the pgstats code that would always require passing around the hash key
> by reference.

I don't see how this improves the situation, but will just make it more
difficult to add a new field that requires padding in the future.

If we are documenting either way, I rather that we just document the need
to pass a key by reference, which is the pattern used in other areas
( see pgss_store and entry_alloc in pg_stat_statements.c )

Others may have a different opinion.

--
Sami