Horton

Re: Parallel Full Hash Join

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Melanie Plageman <melanieplageman@gmail.com>
Cc: Thomas Munro <thomas.munro@gmail.com>, Ian Lawrence Barwick <barwick@gmail.com>, Justin Pryzby <pryzby@telsasoft.com>, vignesh C <vignesh21@gmail.com>, Greg Nancarrow <gregn4422@gmail.com>, Masahiko Sawada <sawada.mshk@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2023-04-08T17:51:54Z
Lists: pgsql-hackers 
Melanie Plageman <melanieplageman@gmail.com> writes:
> Having not done much debugging on buildfarm animals before, I don't
> suppose there is any way to get access to the core itself? I'd like to
> see how many participants the batch barrier had at the time of the
> assertion failure. I assume it was 2, but I just wanted to make sure I
> understand the race.

I don't know about chimaera in particular, but buildfarm animals are
not typically configured to save any build products.  They'd run out
of disk space after awhile :-(.

If you think the number of participants would be useful data, I'd
suggest replacing that Assert with an elog() that prints what you
want to know.

			regards, tom lane

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.