Re: Explain [Analyze] produces parallel scan for select Into table statements.

From: Mithun Cy <mithun(dot)cy(at)enterprisedb(dot)com>
To: Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>
Cc: Robert Haas <robertmhaas(at)gmail(dot)com>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Explain [Analyze] produces parallel scan for select Into table statements.
Date: 2016-03-12 13:50:09
Message-ID: CAD__OujNOskFJxEF_vnkykv1aZuiRYYjSWHskbuA7sGU0asjbQ@mail.gmail.com
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On Sat, Mar 12, 2016 at 2:32 PM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>
wrote:
>With force_parallel_mode=on, I could see many other failures as well. I
think it is better to have test, which tests this functionality with
>force_parallel_mode=regress

as per user manual.
Setting this value to regress has all of the same effects as setting it to
on plus some additional effect that are intended to facilitate automated
regression testing. Normally, messages from a parallel worker are prefixed
with a context line, but a setting of regress suppresses this to guarantee
reproducible results. *Also, the Gather nodes added to plans by this
setting are hidden from the EXPLAIN output so that the output matches what
would be obtained if this setting were turned off. *

And my test is for EXPLAIN statements. I think under regress mode it will
never fail even if parallel scan is used as per above statement.
--
Thanks and Regards
Mithun C Y
EnterpriseDB: http://www.enterprisedb.com

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