Re: Improve description of XLOG_RUNNING_XACTS

On Thu, Jul 21, 2022 at 10:13 PM Ashutosh Bapat
<ashutosh(dot)bapat(dot)oss(at)gmail(dot)com> wrote:
>
> Hi
>
> On Thu, Jul 21, 2022 at 6:44 AM Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
> >
> > Hi,
> >
> > I realized that standby_desc_running_xacts() in standbydesc.c doesn't
> > describe subtransaction XIDs. I've attached the patch to improve the
> > description. Here is an example by pg_wlaldump:
> >
> > * HEAD
> > rmgr: Standby len (rec/tot): 58/ 58, tx: 0, lsn:
> > 0/01D0C608, prev 0/01D0C5D8, desc: RUNNING_XACTS nextXid 1050
> > latestCompletedXid 1047 oldestRunningXid 1048; 1 xacts: 1048
> >
> > * w/ patch
> > rmgr: Standby len (rec/tot): 58/ 58, tx: 0, lsn:
> > 0/01D0C608, prev 0/01D0C5D8, desc: RUNNING_XACTS nextXid 1050
> > latestCompletedXid 1047 oldestRunningXid 1048; 1 xacts: 1048; 1
> > subxacts: 1049
> >
>
> I think this is a good addition to debugging info. +1
>
> If we are going to add 64 subxid numbers then it would help if we
> could be more verbose and print "subxid overflowed" instead of "subxid
> ovf".

Yeah, it looks better so agreed. I've attached an updated patch.

Regards,

--
Masahiko Sawada
EDB: https://www.enterprisedb.com/