Horton

Re: why not parallel seq scan for slow functions

Amit Kapila <amit.kapila16@gmail.com>

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From: Amit Kapila <amit.kapila16@gmail.com>
To: Jeff Janes <jeff.janes@gmail.com>
Cc: Thomas Munro <thomas.munro@enterprisedb.com>, Amit Khandekar <amitdkhan.pg@gmail.com>, Robert Haas <robertmhaas@gmail.com>, Dilip Kumar <dilipbalaut@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2017-09-20T04:15:14Z
Lists: pgsql-hackers 
On Wed, Sep 20, 2017 at 3:05 AM, Jeff Janes <jeff.janes@gmail.com> wrote:
> On Tue, Sep 19, 2017 at 1:17 PM, Thomas Munro
> <thomas.munro@enterprisedb.com> wrote:
>>
>> On Thu, Sep 14, 2017 at 3:19 PM, Amit Kapila <amit.kapila16@gmail.com>
>> wrote:
>> > The attached patch fixes both the review comments as discussed above.
>
>
> that should be fixed by turning costs on the explain, as is the tradition.
>

Right.  BTW, did you get a chance to run the original test (for which
you have reported the problem) with this patch?

-- 
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com

Commits

  1. Rewrite the code that applies scan/join targets to paths.

  2. Teach create_projection_plan to omit projection where possible.

  3. Make the upper part of the planner work by generating and comparing Paths.