Re: Don't keep closed WAL segment in page cache after replay - Mailing list pgsql-hackers

Thanks for the review!

On Tue, Feb 17, 2026 at 9:38 AM Kirill Reshke <reshkekirill@gmail.com> wrote:
> This does not immediately strike me as good reasoning. We have, for
> example, pg_stat_get_wal_senders (or WalSndInitStopping from
> walsenders.h) function which accesses exactly WalSndCtl->walsnds.
> Why don't we simply have another utility function that will return the
> number of active walsenders?

That's true it is an option. I've switched to this approach and
created a WalSndRunning. We only need to know if there's at least one
wal sender running, no need to have a precise number.

I've also added StandbyMode as a condition to restrict this to
replicas. XLogPageRead may be used by the primary when starting up,
and will likely re-read the WAL so releasing cached pages should be
avoided on the primary.