Re: SELECT Query taking 200 ms on PostgreSQL compared to 4 ms on Oracle after migration. - Mailing list pgsql-performance

On Sat, Apr  3, 2021 at 10:41:14AM -0500, Justin Pryzby wrote:
> On Sat, Apr 03, 2021 at 11:39:19AM -0400, Tom Lane wrote:
> > Bruce Momjian <bruce@momjian.us> writes:
> > > On Sat, Apr  3, 2021 at 08:38:18PM +0530, aditya desai wrote:
> > >> Yes, force_parallel_mode is on. Should we set it off?
> > 
> > > Yes.  I bet someone set it without reading our docs:
> > 
> > >     https://www.postgresql.org/docs/13/runtime-config-query.html#RUNTIME-CONFIG-QUERY-OTHER
> > 
> > > -->    Allows the use of parallel queries for testing purposes even in cases
> > > -->    where no performance benefit is expected.
> > 
> > > We might need to clarify this sentence to be clearer it is _only_ for
> > > testing.
> > 
> > I wonder why it is listed under planner options at all, and not under
> > developer options.
> 
> Because it's there to help DBAs catch errors in functions incorrectly marked as
> parallel safe.

Uh, isn't that developer/debugging?

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

  If only the physical world exists, free will is an illusion.