Date: Mon, 2 Feb 2026 17:19:43 +0000
From: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
To: Michael Paquier <michael@paquier.xyz>
Cc: Sami Imseih <samimseih@gmail.com>, Fujii Masao <masao.fujii@gmail.com>,
	pgsql-hackers@lists.postgresql.org,
	Zsolt Parragi <zsolt.parragi@percona.com>
Subject: Re: Flush some statistics within running transactions
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Hi,

On Mon, Feb 02, 2026 at 04:31:48PM +0900, Michael Paquier wrote:
> On Sat, Jan 31, 2026 at 11:16:03AM -0600, Sami Imseih wrote:
> > Also, the anytime flush callback does not need to check if there are
> > any variable-numbered stats to flush. This will not be needed as
> > it is in v4-0004
> > 
> > ```
> > + /*
> > + * Check if there are any non-transactional stats to flush. Avoid
> > + * unnecessarily locking the entry if nothing accumulated.
> > + */
> > + if (!(lstats->counts.numscans > 0 ||
> > +  lstats->counts.tuples_returned > 0 ||
> > +  lstats->counts.tuples_fetched > 0 ||
> > +  lstats->counts.blocks_fetched > 0 ||
> > +  lstats->counts.blocks_hit > 0))
> > + return true;
> > ```
> 
> I think that this kind of check may finish by being expensive.
> Reducing the number of fields to check for a non-flushing state, if
> required, would be preferrable.

Done, in v5 just shared up-thread.

Oh and I forgot to mention that with the new design in v5, then the fix for
the issue discovered by Masao-san is not needed anymore (and so has been removed
from 0001).

Regards,

-- 
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com