Re: injection points for hash aggregation

Jeff Davis <pgsql@j-davis.com>

From: Jeff Davis <pgsql@j-davis.com>
To: pgsql-hackers@postgresql.org
Date: 2025-02-03T23:54:27Z
Lists: pgsql-hackers

Attachments

On Mon, 2025-02-03 at 12:45 -0800, Jeff Davis wrote:
> * The patch allows forcing the partition fan-out to one. I could
> imagine forcing it to a specific value, is there a way to do that?

I hit "send" too quickly and this caused test failures in CI. Attaching
v2.

Changes:

  * a new injection point to force spilling at 1000 tuples so that the
test is deterministic (required some minor refactoring in
hash_agg_check_limits())
  * added a branch to guard against a shift-by-32, which could not
happen in the code before, because the number of partitions was a
minimum of 4
  * minor refactor of hash_agg_set_limits() to avoid an implicit
assumption. This is not directly related, so I added it as a separate
patch.


Regards,
	Jeff Davis

Commits

  1. Injection points for hash aggregation.