Horton

Re: [POC] Faster processing at Gather node

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: Andres Freund <andres@anarazel.de>, Rafia Sabih <rafia.sabih@enterprisedb.com>, PostgreSQL Developers <pgsql-hackers@postgresql.org>
Date: 2017-11-10T03:06:39Z
Lists: pgsql-hackers 
On Thu, Nov 9, 2017 at 9:31 PM, Amit Kapila <amit.kapila16@gmail.com> wrote:
> Have you set force_parallel_mode=regress; before running the
> statement?

Yes, I tried that first.

> If so, then why you need to tune other parallel query
> related parameters?

Because I couldn't get it to break the other way, I then tried this.

Instead of asking me what I did, can you tell me what I need to do?
Maybe a self-contained reproducible test case including exactly what
goes wrong on your end?

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

Commits

  1. C comment: fix wording about shared memory message queue

  2. shm_mq: Have the receiver set the sender's less frequently.

  3. shm_mq: Reduce spinlock usage.

  4. Remove use of byte-masking macros in record_image_cmp

  5. Remove memory leak protection from Gather and Gather Merge nodes.

  6. Avoid projecting tuples unnecessarily in Gather and Gather Merge.

  7. Tweak use of ExecContextForcesOids by Gather (Merge).

  8. Pass eflags down to parallel workers.

  9. Disable installcheck tests for test_session_hooks

  10. First-draft release notes for 10.1.

  11. Remove TupleDesc remapping logic from tqueue.c.

  12. Avoid memory leaks when a GatherMerge node is rescanned.

  13. Code review for nodeGatherMerge.c.

  14. Add a Gather Merge executor node.

  15. Push scan/join target list beneath Gather when possible.