Horton

Re: Parallel Full Hash Join

Thomas Munro <thomas.munro@gmail.com>

View thread View on postgr.es
From: Thomas Munro <thomas.munro@gmail.com>
To: Melanie Plageman <melanieplageman@gmail.com>
Cc: 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: 2022-04-08T11:29:32Z
Lists: pgsql-hackers

Attachments

On Wed, Jan 12, 2022 at 10:30 AM Melanie Plageman
<melanieplageman@gmail.com> wrote:
> On Fri, Nov 26, 2021 at 3:11 PM Thomas Munro <thomas.munro@gmail.com> wrote:
> > #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
>
> I believe this assert can be safely removed.

Agreed.

I was looking at this with a view to committing it, but I need more
time.  This will be at the front of my queue when the tree reopens.
I'm trying to find the tooling I had somewhere that could let you test
attaching and detaching at every phase.

The attached version is just pgindent'd.

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.