Message-ID: <973a9511ab3c10d77ee46c4b2cd3bc3210a51550.camel@j-davis.com>
Subject: Re: Significant performance issues with array_agg() + HashAggregate
 plans on Postgres 17
From: Jeff Davis <pgsql@j-davis.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Scott Carey <scott.carey@algonomy.com>, David Rowley
 <dgrowleyml@gmail.com>,  pgsql-performance@lists.postgresql.org
Date: Fri, 03 Apr 2026 13:01:38 -0700
In-Reply-To: <3829071.1775246182@sss.pgh.pa.us>
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On Fri, 2026-04-03 at 15:56 -0400, Tom Lane wrote:
> Would it make sense to accumulate those values in a separate field
> child_mem_allocated, rather than redefining what mem_allocated
> means?

I think so unless we can't afford the new field for some reason. It
would be convenient to have the single-context-total available when
deleting the context.

I'll try a quick patch. I'll need to be sure that we can properly
decrement the total in all paths.

Regards,
	Jeff Davis