Re: Fix BUG #17335: Duplicate result rows in Gather node
David Rowley <dgrowleyml@gmail.com>
From: David Rowley <dgrowleyml@gmail.com>
To: Yura Sokolov <y.sokolov@postgrespro.ru>
Cc: PostgreSQL Developers <pgsql-hackers@lists.postgresql.org>
Date: 2022-01-25T08:20:25Z
Lists: pgsql-hackers
On Tue, 25 Jan 2022 at 20:03, David Rowley <dgrowleyml@gmail.com> wrote: > > On Tue, 25 Jan 2022 at 17:35, Yura Sokolov <y.sokolov@postgrespro.ru> wrote: > > And another attempt to fix tests volatility. > > FWIW, I had not really seen the point in adding a test for this. I > did however see a point in it with your original patch. It seemed > useful there to verify that Gather and GatherMerge did what we > expected with 1 worker. I ended up pushing just the last patch I sent. The reason I didn't think it was worth adding a new test was that no tests were added in the original commit. Existing tests did cover it, but here we're just restoring the original behaviour for one simple case. The test in your patch just seemed a bit more hassle than it was worth. I struggle to imagine how we'll break this again. David
Commits
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Consider parallel awareness when removing single-child Appends
- 2ccd8fb29d74 12.10 landed
- f8807e7742e5 13.6 landed
- 357ff66153b4 14.2 landed
- f9a74c1498d2 15.0 landed
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Suppress Append and MergeAppend plan nodes that have a single child.
- 8edd0e79460b 12.0 cited