Re: explain analyze output with parallel workers - question about meaning of information for explain.depesz.com

From: Ashutosh Bapat <ashutosh(dot)bapat(at)enterprisedb(dot)com>
To: Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>
Cc: Hubert Lubaczewski <depesz(at)depesz(dot)com>, pgsql-hackers mailing list <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: explain analyze output with parallel workers - question about meaning of information for explain.depesz.com
Date: 2017-11-27 08:34:00
Message-ID: CAFjFpRcL7+s1b-Y8amz9QkbHB+r6+ZV3J_rCUHs+bEbf47ZL7g@mail.gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

On Sat, Nov 25, 2017 at 7:08 AM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>>
>> It looks that the actual time is really actual time, and loops is
>> "worker nodes + 1".
>>
>> Is that really the case?
>>
>
> I think so.
>

To add to what Amit has explained. The + 1 is for the leader (the
backend running the whole query) which also runs the parallel plan if
it gets time between fetching rows from the workers.

--
Best Wishes,
Ashutosh Bapat
EnterpriseDB Corporation
The Postgres Database Company

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Amit Kapila 2017-11-27 09:04:09 Re: [HACKERS] Challenges preventing us moving to 64 bit transaction id (XID)?
Previous Message Magnus Hagander 2017-11-27 08:32:05 Re: Typo in config_default.pl comment