Horton

Re: Parallel Full Hash Join

Thomas Munro <thomas.munro@gmail.com>

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From: Thomas Munro <thomas.munro@gmail.com>
To: Justin Pryzby <pryzby@telsasoft.com>
Cc: Melanie Plageman <melanieplageman@gmail.com>, vignesh C <vignesh21@gmail.com>, Greg Nancarrow <gregn4422@gmail.com>, Masahiko Sawada <sawada.mshk@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2021-11-26T20:11:21Z
Lists: pgsql-hackers 
On Sun, Nov 21, 2021 at 4:48 PM Justin Pryzby <pryzby@telsasoft.com> wrote:
> On Wed, Nov 17, 2021 at 01:45:06PM -0500, Melanie Plageman wrote:
> > Yes, this looks like that issue.
> >
> > I've attached a v8 set with the fix I suggested in [1] included.
> > (I added it to 0001).
>
> This is still crashing :(
> https://cirrus-ci.com/task/6738329224871936
> https://cirrus-ci.com/task/4895130286030848

I added a core file backtrace to cfbot's CI recipe a few days ago, so
now we have:

https://cirrus-ci.com/task/5676480098205696

#3 0x00000000009cf57e in ExceptionalCondition (conditionName=0x29cae8
"BarrierParticipants(&accessor->shared->batch_barrier) == 1",
errorType=<optimized out>, fileName=0x2ae561 "nodeHash.c",
lineNumber=lineNumber@entry=2224) at assert.c:69
No locals.
#4 0x000000000071575e in ExecParallelScanHashTableForUnmatched
(hjstate=hjstate@entry=0x80a60a3c8,
econtext=econtext@entry=0x80a60ae98) at nodeHash.c:2224

Commits

  1. Remove overzealous assertion from PHJ.

  2. Remove comment obsoleted by 11c2d6fd.

  3. Parallel Hash Full Join.

  4. Improve the naming of Parallel Hash Join phases.

  5. Update the names of Parallel Hash Join phases.

  6. Add BarrierArriveAndDetachExceptLast().

  7. Mop-up for wait event naming issues.

  8. Push tuple limits through Gather and Gather Merge.