Re: pgsql: Add memory/disk usage for Window aggregate nodes in EXPLAIN.

David Rowley <dgrowleyml@gmail.com>

From: David Rowley <dgrowleyml@gmail.com>
To: Christoph Berg <myon@debian.org>
Cc: Tatsuo Ishii <ishii@postgresql.org>, pgsql-hackers@lists.postgresql.org
Date: 2025-03-31T20:11:13Z
Lists: pgsql-hackers
On Tue, 1 Apr 2025 at 04:40, Christoph Berg <myon@debian.org> wrote:
> -   Storage: Disk  Maximum Storage: NkB
> +   Storage: Memory  Maximum Storage: NkB
>     ->  Function Scan on generate_series a (actual time=N.N..N.N rows=N.N loops=N)

We'll probably just need to bump that 2000 row count to something a
bit more for 32-bit.

Any chance you could share the output of:

explain (analyze,buffers off,costs off) select sum(n) over() from
generate_series(1,2000) a(n);

Could you maybe also do a binary search for the number of rows where
it goes to disk by adjusting the 2000 up in some increments until the
Storage method is disk? (Not that I think we should set it to the
minimum, but it would be good to not set it too much higher than we
need to)

David



Commits

  1. Fix failing regression test on x86-32 machines

  2. Add memory/disk usage for Window aggregate nodes in EXPLAIN.