Re: System username in pg_stat_activity

Hi,

On Thu, Jan 11, 2024 at 02:24:58PM +0100, Magnus Hagander wrote:
> On Wed, Jan 10, 2024 at 3:12 PM Bertrand Drouvot
>  wrote:
> >
> > If we go the 2 fields way, then what about auth_identity and auth_method then?
> 
> 
> Here is an updated patch based on this idea.

Thanks!

+     
+      
+       auth_method text
+      
+      
+       The authentication method used for authenticating the connection, or
+       NULL for background processes.
+      

I'm wondering if it would make sense to populate it for parallel workers too.
I think it's doable thanks to d951052, but I'm not sure it's worth it (one could
join based on the leader_pid though). OTOH that would be consistent with
how the SYSTEM_USER behaves with parallel workers (it's populated).

+      
+       auth_identity text
+      
+      
+       The identity (if any) that the user presented during the authentication
+       cycle before they were assigned a database role.  Contains the same
+       value as 

Same remark regarding the parallel workers case +:

- Would it be better to use the `name` datatype for auth_identity?
- what about "Contains the same value as the identity part in "?

+                       /*
+                        * Trust doesn't set_authn_id(), but we still need to store the
+                        * auth_method
+                        */
+                       MyClientConnectionInfo.auth_method = uaTrust;

+1, I think it is useful here to provide "trust" and not a NULL value in the
context of this patch.

+# pg_stat_activity shold contain trust and empty string for trust auth

typo: s/shold/should/

+# Users with md5 auth should show both auth method and name in pg_stat_activity

what about "show both auth method and identity"?

Regards,

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