Horton

Re: Parallel Index Scans

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: Anastasia Lubennikova <a.lubennikova@postgrespro.ru>, Anastasia Lubennikova <lubennikovaav@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>, Rahila Syed <rahilasyed.90@gmail.com>
Date: 2017-02-15T12:47:59Z
Lists: pgsql-hackers 
On Wed, Feb 15, 2017 at 7:11 AM, Amit Kapila <amit.kapila16@gmail.com> wrote:
> Here second part of the comment (but have not yet advanced ..) seems
> to be slightly misleading because this state has nothing to do with
> the advancement of scan keys.
>
> I have not changed this because I am not sure what you have in mind.

OK, I rewrote that to be (hopefully) more clear.

> I have verified all your changes and they look good to me.

Cool.  Committed.  I also changed the wait event to be BtreePage in
the docs + pg_stat_activity, and moved it into alphabetical order in
the switch and the enum.

>> I can't easily test this because your second patch doesn't apply,
>
> I have tried and it works for me on latest code except for one test
> output file which could have been excluded.  I wonder whether you are
> first applying the GUC related patch [1] before applying the optimizer
> support related patch.  In anycase, to avoid confusion I am attaching
> all the three patches with this e-mail.

Oh, duh.  I forgot about the prerequisite patch.  Sorry.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

Commits

  1. Replace min_parallel_relation_size with two new GUCs.

  2. Factor out logic for computing number of parallel workers.

  3. Support condition variables.

  4. Allow parallel custom and foreign scans.

  5. Add a C API for parallel heap scans.