Re: pgsql: Add parallel-aware hash joins.

Thomas Munro <thomas.munro@enterprisedb.com>

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From: Thomas Munro <thomas.munro@enterprisedb.com>

To: Andres Freund <andres@anarazel.de>

Cc: pgsql-committers <pgsql-committers@postgresql.org>

Date: 2017-12-26T10:48:37Z

Lists: pgsql-hackers

Attachments

fix-phj-writing-assertion-failure.patch (application/octet-stream) patch

On Fri, Dec 22, 2017 at 9:22 PM, Andres Freund <andres@anarazel.de> wrote:
> On 2017-12-22 21:16:10 +1300, Thomas Munro wrote:
>> Andres, your machine francolin crashed -- got a core file?
>
> Unfortunately not - it appears the buildfarm cleared it away :(

I now have a workload that fails within a few minutes or so on master.
I see the problem: MultiExecParallelHash() needs to run
sts_end_write() *before* detaching from grow_batches_barrier.  My test
case doesn't fail with the attached patch applied.

I'll address the instability of the regression test output separately.
Sorry for the delay, due to the time of year.

-- 
Thomas Munro
http://www.enterprisedb.com

Commits

Update obsolete sentence in README.parallel.
- 28e04155f17c 11.0 cited
Rewrite ConditionVariableBroadcast() to avoid live-lock.
- aced5a92bf46 11.0 cited
Tweak parallel hash join test case in hopes of improving stability.
- 934c7986f4a0 11.0 landed
Rename pg_rewind's copy_file_range() to avoid conflict with new linux syscall.
- 3e68686e2c55 11.0 cited
Fix some minor errors in new PHJ code.
- 6fcde2406304 11.0 landed
Fix EXPLAIN ANALYZE output for Parallel Hash.
- 93ea78b17c47 11.0 landed
Fix rare assertion failure in parallel hash join.
- f83040c62a78 11.0 landed
Cancel CV sleep during subtransaction abort.
- f3decdc94ea3 10.2 landed
- 59d1e2b95a82 11.0 landed
Add parallel-aware hash joins.
- 1804284042e6 11.0 cited
Fix EXPLAIN ANALYZE of hash join when the leader doesn't participate.
- 5bcf389ecfd4 11.0 cited
Add some regression tests that exercise hash join code.
- fa330f9adf4e 11.0 cited