Re: Expose lock group leader pid in pg_stat_activity

[Julien Rouhaud]

On Thu, Feb 06, 2020 at 09:24:16AM +0900, Michael Paquier wrote:
> On Wed, Feb 05, 2020 at 07:57:20AM +0100, Julien Rouhaud wrote:
> > This looks good, thanks a lot!
> 
> Thanks for double-checking.  And done.

Thanks!

While on the topic, is there any reason why the backend stays a group leader
for the rest of its lifetime, and should we change that?

Also, while reading ProcKill, I noticed a typo in a comment:

    /*
     * Detach from any lock group of which we are a member.  If the leader
-    * exist before all other group members, it's PGPROC will remain allocated
+    * exist before all other group members, its PGPROC will remain allocated
     * until the last group process exits; that process must return the
     * leader's PGPROC to the appropriate list.
     */

diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c
index 32df8c85a1..eb321f72ea 100644
--- a/src/backend/storage/lmgr/proc.c
+++ b/src/backend/storage/lmgr/proc.c
@@ -851,7 +851,7 @@ ProcKill(int code, Datum arg)
 
        /*
         * Detach from any lock group of which we are a member.  If the leader
-        * exist before all other group members, it's PGPROC will remain 
allocated
+        * exist before all other group members, its PGPROC will remain 
allocated
         * until the last group process exits; that process must return the
         * leader's PGPROC to the appropriate list.
         */