Re: make add_paths_to_append_rel aware of startup cost

Thomas Munro <thomas(dot)munro(at)gmail(dot)com> writes:

> On Thu, Oct 5, 2023 at 9:07 PM David Rowley <dgrowleyml(at)gmail(dot)com> wrote:
>> Thanks. Pushed.
>
> FYI somehow this plan from a8a968a8212e flipped in this run:
>
> === dumping /home/bf/bf-build/mylodon/HEAD/pgsql.build/testrun/recovery/027_stream_regress/data/regression.diffs
> ===
> diff -U3 /home/bf/bf-build/mylodon/HEAD/pgsql/src/test/regress/expected/union.out
> /home/bf/bf-build/mylodon/HEAD/pgsql.build/testrun/recovery/027_stream_regress/data/results/union.out
> --- /home/bf/bf-build/mylodon/HEAD/pgsql/src/test/regress/expected/union.out
> 2024-01-15 00:31:13.947555940 +0000
> +++ /home/bf/bf-build/mylodon/HEAD/pgsql.build/testrun/recovery/027_stream_regress/data/results/union.out
> 2024-02-14 00:06:17.075584839 +0000
> @@ -1447,9 +1447,9 @@
> -> Append
> -> Nested Loop
> Join Filter: (t1.tenthous = t2.tenthous)
> - -> Seq Scan on tenk1 t1
> + -> Seq Scan on tenk2 t2
> -> Materialize
> - -> Seq Scan on tenk2 t2
> + -> Seq Scan on tenk1 t1
> -> Result
> (8 rows)
>
> https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=mylodon&dt=2024-02-14%2000%3A01%3A03

Thanks for this information! I will take a look at this.

--
Best Regards
Andy Fan