Horton

Re: Hash index build performance tweak from sorting

Simon Riggs <simon.riggs@enterprisedb.com>

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From: Simon Riggs <simon.riggs@enterprisedb.com>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2022-05-10T09:42:59Z
Lists: pgsql-hackers

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On Sat, 30 Apr 2022 at 12:12, Amit Kapila <amit.kapila16@gmail.com> wrote:
>
> Few comments on the patch:
> 1. I think it is better to use DatumGetUInt32 to fetch the hash key as
> the nearby code is using.
> 2. You may want to change the below comment in HSpool
> /*
> * We sort the hash keys based on the buckets they belong to. Below masks
> * are used in _hash_hashkey2bucket to determine the bucket of given hash
> * key.
> */

Addressed in new patch, v2.

On Wed, 4 May 2022 at 11:27, Amit Kapila <amit.kapila16@gmail.com> wrote:
>
> So, we should go with this unless someone else sees any flaw here.

Cool, thanks.

-- 
Simon Riggs                http://www.EnterpriseDB.com/

Commits

  1. Speedup hash index builds by skipping needless binary searches

  2. Improve speed of hash index build.

  3. Change hash indexes to store only the hash code rather than the whole indexed