Re: [PATCH] Add extra statistics to explain for Nested Loop

On Tue, Apr 05, 2022 at 05:14:09PM -0400, Greg Stark wrote:
> This is not passing regression tests due to some details of the plan
> output - marking Waiting on Author:

It's unstable due to parallel workers.
I'm not sure what the usual workarounds here.
Maybe set parallel_leader_participation=no for this test.

> diff -w -U3 c:/cirrus/src/test/regress/expected/partition_prune.out
> c:/cirrus/src/test/recovery/tmp_check/results/partition_prune.out
> --- c:/cirrus/src/test/regress/expected/partition_prune.out 2022-04-05
> 17:00:25.433576100 +0000
> +++ c:/cirrus/src/test/recovery/tmp_check/results/partition_prune.out
> 2022-04-05 17:18:30.092203500 +0000
> @@ -2251,10 +2251,7 @@
> Workers Planned: 2
> Workers Launched: N
> -> Parallel Seq Scan on public.lprt_b (actual rows=N loops=N)
> - Loop Min Rows: N Max Rows: N Total Rows: N
> Output: lprt_b.b
> - Worker 0: actual rows=N loops=N
> - Worker 1: actual rows=N loops=N
> -> Materialize (actual rows=N loops=N)
> Loop Min Rows: N Max Rows: N Total Rows: N
> Output: lprt_a.a
> @@ -2263,10 +2260,8 @@
> Workers Planned: 1
> Workers Launched: N
> -> Parallel Seq Scan on public.lprt_a (actual rows=N loops=N)
> - Loop Min Rows: N Max Rows: N Total Rows: N
> Output: lprt_a.a
> - Worker 0: actual rows=N loops=N
> -(24 rows)
> +(19 rows)