On Sat, Apr 1, 2017 at 12:25 AM, Andres Freund <andres@anarazel.de> wrote:
> Hi,
>
> As visible in [1], the explain analyze codepaths of parallel query isn't
> exercised in the tests. That used to be not entirely trivial if the
> output was to be displayed (due to timing), but we should be able to do
> that now that we have the SUMMARY option.
>
> E.g.
> SET max_parallel_workers = 0;
> EXPLAIN (analyze, timing off, summary off, costs off) SELECT * FROM blarg2 WHERE generate_series < 0;
> ┌───────────────────────────────────────────────────────────┐
> │ QUERY PLAN │
> ├───────────────────────────────────────────────────────────┤
> │ Gather (actual rows=0 loops=1) │
> │ Workers Planned: 10 │
> │ Workers Launched: 0 │
> │ -> Parallel Seq Scan on blarg2 (actual rows=0 loops=1) │
> │ Filter: (generate_series < 0) │
> │ Rows Removed by Filter: 10000000 │
> └───────────────────────────────────────────────────────────┘
>
> should be reproducible. I'd suggest additionally adding one tests that
> throws the EXPLAIN output away, but actually enables paralellism.
>
> Greetings,
>
> Andres Freund
>
> [1] https://coverage.postgresql.org/src/backend/executor/execParallel.c.gcov.html
Please find the attached for the same.
--
Regards,
Rafia Sabih
EnterpriseDB: http://www.enterprisedb.com/
