Re: Add pg_stat_kind_info system view

Hi,

On Wed, Jun 24, 2026 at 01:12:09PM +0900, Michael Paquier wrote:
> On Thu, Jun 18, 2026 at 04:54:36PM +0000, Tristan Partin wrote:
> > On Mon Jun 8, 2026 at 12:16 AM UTC, Michael Paquier wrote:
> >> On Thu, Jun 04, 2026 at 04:59:00PM +0000, Tristan Partin wrote:
> >>> I believe that I also captured this correctly in v2.
> >>
> >> No v2 of the patch has been attached.  :D

Thanks for the patch, that looks like an useful addition to me.

A few comments:

=== 1

+++ b/src/backend/utils/adt/pgstatfuncs.c
@@ -30,6 +30,8 @@
 #include "storage/procarray.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
+#include "utils/pgstat_internal.h"

But header in pgstat_internal.h mentions:

"
 * Definitions for the PostgreSQL cumulative statistics system that should
 * only be needed by files implementing statistics support (rather than ones
 * reporting / querying stats).

"

So it looks like that we are breaking this convention here. Maybe add helper
function(s)?

=== 2

+  /* For fixed-amount kinds, count is always 1. The entry is stored in
+   * PgStat_ShmemControl. If it is not a fixed-amount, then report the
+   * count of entries if tracked, or NULL if not tracked.
+   */

comment style is not right.

=== 3

+  /* For fixed-amount kinds, count is always 1.

Why not report NULL for fixed-amount kinds too? The track_entry_count field is
documented as being for variable-numbered stats only, so the count would only be
reported for custom variable-numbered kinds that set it to true.

Regards,

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