| From: | Sami Imseih <samimseih(dot)pg(at)gmail(dot)com> |
|---|---|
| To: | Xuneng Zhou <xunengzhou(at)gmail(dot)com> |
| Cc: | Alexander Korotkov <aekorotkov(at)gmail(dot)com>, Álvaro Herrera <alvherre(at)kurilemu(dot)de>, Postgres hackers <pgsql-hackers(at)lists(dot)postgresql(dot)org> |
| Subject: | Re: Reject WAIT FOR earlier in transaction-snapshot mode |
| Date: | 2026-09-17 02:50:26 |
| Message-ID: | CAN12+YLvZW7ScNdWZchKz=9Zyc4f3ZfFjVwz=HO4M0nfcOeDOQ@mail.gmail.com |
| Views: | Whole Thread | Raw Message | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
> > I don't think there is a good use-case here where someone will do:
> >
> > BEGIN ISOLATION LEVEL REPEATBLE READ; WAIT FOR LSN ...;
> > SELECT ...
>
> Can you please elaborate on why this is not a good use-case?
Because I was thinking that calling WAIT FOR LSN before
BEGIN ISOLATION LEVEL ... is equivalent to calling it after, since the
transaction snapshot is not taken until the first SELECT. However, I can
see how requiring that order could be problematic, especially when the
driver issues BEGIN ISOLATION LEVEL ... automatically.
--
Sami Imseih
Amazon Web Services (AWS).
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Tom Lane | 2026-09-17 02:51:59 | Re: remove_useless_joins vs. bug #19560 |
| Previous Message | Michael Paquier | 2026-09-17 02:48:26 | Re: DSA_ALLOC_NO_OOM vs dsm_create ERROR leaving a half-initialized pgstats hash entry |