| From: | David Rowley <dgrowleyml(at)gmail(dot)com> |
|---|---|
| To: | Andrei Lepikhov <lepihov(at)gmail(dot)com> |
| Cc: | PostgreSQL Developers <pgsql-hackers(at)lists(dot)postgresql(dot)org> |
| Subject: | Re: Add ExprState hashing for GROUP BY and hashed SubPlans |
| Date: | 2024-10-31 23:17:27 |
| Message-ID: | CAApHDvometdQAZo+S=cn5Ojm7NzurAAWAMex4FCeMoqjwMVtDA@mail.gmail.com |
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| Lists: | pgsql-hackers |
On Thu, 31 Oct 2024 at 15:30, Andrei Lepikhov <lepihov(at)gmail(dot)com> wrote:
> Comparing the master with and without your patch, the first, I see is
> more extensive usage of memory (see complete explains in the attachment):
>
> Current master:
> Batches: 1 Memory Usage: 74513kB
> Patched:
> Batches: 261 Memory Usage: 527905kB Disk Usage: 4832656kB
Thanks for testing that. I had forgotten to adjust the storage
location for the hash initial value when I rebased the patch against
the changes made in 9ca67658d. I've fixed that in the attached patch.
The patched version comes out faster for me now:
master: Execution Time: 15515.401 ms
v4 patch: Execution Time: 15024.395 ms
David
| Attachment | Content-Type | Size |
|---|---|---|
| v4-0001-Use-ExprStates-for-hashing-in-GROUP-BY-and-SubPla.patch | application/octet-stream | 19.1 KB |
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