Horton

Re: Parallel Index Scans

Amit Kapila <amit.kapila16@gmail.com>

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From: Amit Kapila <amit.kapila16@gmail.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Michael Banck <michael.banck@credativ.de>, Anastasia Lubennikova <a.lubennikova@postgrespro.ru>, Anastasia Lubennikova <lubennikovaav@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>, Rahila Syed <rahilasyed.90@gmail.com>
Date: 2017-03-06T13:46:15Z
Lists: pgsql-hackers 
On Mon, Mar 6, 2017 at 6:49 PM, Robert Haas <robertmhaas@gmail.com> wrote:
> On Mon, Mar 6, 2017 at 6:33 AM, Amit Kapila <amit.kapila16@gmail.com> wrote:
>
> I was going to do it after index and index-only scans and parallel
> bitmap heap scan were committed, but I've been holding off on
> committing parallel bitmap heap scan waiting for Andres to fix the
> simplehash regressions, so maybe I should just go do an update now and
> another one later once that goes in.
>

As you wish, but one point to note is that as of now parallelism for
index scans can be influenced by table level parameter
parallel_workers.  It sounds slightly awkward, but if we want to keep
that way, then maybe we can update the docs to indicate the same.
Another option is to have a separate parameter for index scans.


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

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.