Horton

Re: Memory-Bounded Hash Aggregation

Tomas Vondra <tomas.vondra@2ndquadrant.com>

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From: Tomas Vondra <tomas.vondra@2ndquadrant.com>
To: Jeff Davis <pgsql@j-davis.com>
Cc: andres@anarazel.de, Taylor Vesely <tvesely@pivotal.io>, Adam Lee <ali@pivotal.io>, Melanie Plageman <mplageman@pivotal.io>, pgsql-hackers@postgresql.org
Date: 2019-12-05T22:04:57Z
Lists: pgsql-hackers 
On Thu, Dec 05, 2019 at 12:55:51PM -0800, Jeff Davis wrote:
>On Thu, 2019-11-28 at 18:46 +0100, Tomas Vondra wrote:
>> And it's not clear to me why we should remove part of the comment
>> before
>> TupleHashTableHash.
>
>It looks like 5dfc1981 changed the signature of TupleHashTableHash
>without updating the comment, so it doesn't really make sense any more.
>I just updated the comment as a part of my patch, but it's not related.
>
>Andres, comments? Maybe we can just commit a fix for that comment and
>take it out of my patch.
>

+1 to push that as an independent fix


regards

-- 
Tomas Vondra                  http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Commits

  1. Fix costing for disk-based hash aggregation.

  2. Fixes for Disk-based Hash Aggregation.

  3. Disk-based Hash Aggregation.

  4. Extend ExecBuildAggTrans() to support a NULL pointer check.

  5. Save calculated transitionSpace in Agg node.

  6. Minor refactor of nodeAgg.c.

  7. Logical Tape Set: lazily allocate read buffer.

  8. Introduce TupleHashTableHash() and LookupTupleHashEntryHash().

  9. Logical Tape Set: use min heap for freelist.

  10. Fix comments in execGrouping.c

  11. Avoid integer overflow while sifting-up a heap in tuplesort.c.

  12. Make the overflow guards in ExecChooseHashTableSize be more protective.

  13. Improve performance of our private version of qsort. Per recent testing,