Re: test: avoid redundant standby catchup in 049_wait_for_lsn

On Sat, Apr 18, 2026 at 10:58 AM Alexander Korotkov
<aekorotkov(at)gmail(dot)com> wrote:
> On Sat, Apr 18, 2026 at 7:20 AM Xuneng Zhou <xunengzhou(at)gmail(dot)com> wrote:
> >> On Fri, Apr 17, 2026 at 08:25:35PM +0800, Xuneng Zhou wrote:
> >> > The change preserves the same coverage while removing one redundant
> >> > replay catch-up on the delayed standby. It appears to reduce the test
> >> > runtime by about 7 seconds, though I have looked into why much of the
> >> > improvement comes from this change alone.
> >>
> >> Alexander may think differently and remove that, but I disagree. The
> >> test is clearly written so as we want two wait checks to happen, for
> >> for CREATE FUNCTION, and one for CREATE PROCEDURE. Removing the first
> >> check to keep only the second one removes its meaning. In short, I
> >> see nothing wrong to deal with here.
> >
> >
> > Thank you for the review. I agree that the two wait checks serve distinct purposes and are not redundant. The main motivation for this patch was efficiency. In my testing, the new test added approximately 7 seconds to the runtime, while the creation of the procedure and function completed quickly. I suspect the latency stems from the wait-for-catch-up step. When I removed it, the test runtime dropped by about 7 seconds.I haven't yet investigated why the wait is so costly in this case. I should probably look into that before proposing this change.
>
> On my laptop the time needed to run t/049_wait_for_lsn.pl also drops
> from 20 secs to 12 secs. The influence to the runtime of the whole
> test suite in parallel would be not that big as CPU time only drops
> from 2.16 sec to 2.07 sec. But anyway that's pretty significant.
> I've revised comment message a bit and surrounding comments. I'm
> going to push this if no objections.

Pushed.

------
Regards,
Alexander Korotkov
Supabase