Thread: subtransaction performance
Hi,
I stumbled over:
I wonder if SAVEPOINT / subtransaction performance has been boosted since the blog was written.
Cheers
On Fri, Oct 7, 2022 at 03:23:27PM -0700, Zhihong Yu wrote: > Hi, > I stumbled over: > > https://about.gitlab.com/blog/2021/09/29/ > why-we-spent-the-last-month-eliminating-postgresql-subtransactions/ > > I wonder if SAVEPOINT / subtransaction performance has been boosted since the > blog was written. No, I have not seen any changes in this area since then. Seems there are two problems --- the 64 cache per session and the 64k on the replica. In both cases, it seems sizing is not optimal, but sizing is never optimal. I guess we can look at allowing manual size adjustment, automatic size adjustment, or a different approach that is more graceful for larger savepoint workloads. -- Bruce Momjian <bruce@momjian.us> https://momjian.us EDB https://enterprisedb.com Indecision is a decision. Inaction is an action. Mark Batterson
On Mon, Oct 10, 2022 at 02:20:37PM -0400, Bruce Momjian wrote:
> On Fri, Oct 7, 2022 at 03:23:27PM -0700, Zhihong Yu wrote:
>> I wonder if SAVEPOINT / subtransaction performance has been boosted since the
>> blog was written.
>
> No, I have not seen any changes in this area since then. Seems there
> are two problems --- the 64 cache per session and the 64k on the
> replica. In both cases, it seems sizing is not optimal, but sizing is
> never optimal. I guess we can look at allowing manual size adjustment,
> automatic size adjustment, or a different approach that is more graceful
> for larger savepoint workloads.
I believe the following commitfest entries might be relevant to this
discussion:
https://commitfest.postgresql.org/39/2627/
https://commitfest.postgresql.org/39/3514/
https://commitfest.postgresql.org/39/3806/
--
Nathan Bossart
Amazon Web Services: https://aws.amazon.com
On Mon, Oct 10, 2022 at 08:34:33PM -0700, Nathan Bossart wrote: > On Mon, Oct 10, 2022 at 02:20:37PM -0400, Bruce Momjian wrote: > > On Fri, Oct 7, 2022 at 03:23:27PM -0700, Zhihong Yu wrote: > >> I wonder if SAVEPOINT / subtransaction performance has been boosted since the > >> blog was written. > > > > No, I have not seen any changes in this area since then. Seems there > > are two problems --- the 64 cache per session and the 64k on the > > replica. In both cases, it seems sizing is not optimal, but sizing is > > never optimal. I guess we can look at allowing manual size adjustment, > > automatic size adjustment, or a different approach that is more graceful > > for larger savepoint workloads. > > I believe the following commitfest entries might be relevant to this > discussion: > > https://commitfest.postgresql.org/39/2627/ > https://commitfest.postgresql.org/39/3514/ > https://commitfest.postgresql.org/39/3806/ Wow, odd that I missed those. Yes, they are very relevant. :-) The only other idea I had was to report such overflows, but these are better. -- Bruce Momjian <bruce@momjian.us> https://momjian.us EDB https://enterprisedb.com Indecision is a decision. Inaction is an action. Mark Batterson