Horton

Re: A qsort template

Thomas Munro <thomas.munro@gmail.com>

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From: Thomas Munro <thomas.munro@gmail.com>
To: John Naylor <john.naylor@enterprisedb.com>
Cc: Peter Geoghegan <pg@bowt.ie>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2022-03-31T21:42:59Z
Lists: pgsql-hackers 
On Thu, Mar 31, 2022 at 11:09 PM John Naylor
<john.naylor@enterprisedb.com> wrote:
> In a couple days I'm going to commit the v3 patch "accelerate tuple
> sorting for common types" as-is after giving it one more look, barring
> objections.

Hi John,

Thanks so much for all the work you've done here!  I feel bad that I
lobbed so many experimental patches in here and then ran away due to
lack of cycles.  That particular patch (the one cfbot has been chewing
on all this time) does indeed seem committable, despite the
deficiencies/opportunities listed in comments.  It's nice to reduce
code duplication, it gives the right answers, and it goes faster.

> I started towards incorporating the change in insertion sort threshold
> (part of 0010), but that caused regression test failures, so that will
> have to wait for a bit of analysis and retesting. (My earlier tests
> were done in a separate module.)
>
> The rest in this series that I looked at closely were either
> refactoring or could use some minor tweaks so likely v16 material.

Looking forward to it.

Commits

  1. Remove debug messages from tuplesort_sort_memtuples()

  2. Fix performance regression in tuplesort specializations

  3. Fix tuplesort optimization for CLUSTER-on-expression.

  4. Initial pgindent and pgperltidy run for v14.

  5. Specialize checkpointer sort functions.

  6. Use sort_template.h for qsort() and qsort_arg().

  7. Use sort_template.h for qsort_tuple() and qsort_ssup().

  8. Add sort_template.h for making sort functions.

  9. Use abbreviated keys for faster sorting of text datums.