| From: | Bruce Momjian <bruce(at)momjian(dot)us> |
|---|---|
| To: | Euler Taveira <euler(at)eulerto(dot)com> |
| Cc: | Kyotaro HORIGUCHI <horiguchi(dot)kyotaro(at)lab(dot)ntt(dot)co(dot)jp>, pgsql-hackers(at)lists(dot)postgresql(dot)org |
| Subject: | Re: Lifetime of commit timestamps |
| Date: | 2023-11-17 21:01:27 |
| Message-ID: | ZVfUp4nLj7RnqErM@momjian.us |
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| Lists: | pgsql-hackers |
On Fri, Nov 17, 2023 at 03:39:14PM -0300, Euler Taveira wrote:
> On Mon, Nov 13, 2023, at 9:47 PM, Bruce Momjian wrote:
>
> Is this documentation change still relevant?
>
>
> I think so. AFAICS nothing changed. Unless you read the source code, it is not
> clear that VACUUM removes the information for frozen tuples. They are decoupled
> (but executed in the same routine for convenience), hence, someone can ask why
> the pg_xact_commit_timestamp() returns NULL for a transaction that was executed
> *after* you enable track_commit_timestamp. The answer is the design used a
> existing mechanism to clean up data in order to avoid creating a new one.
Okay, I have developed the attached patch based on Horiguchi-san's
version.
--
Bruce Momjian <bruce(at)momjian(dot)us> https://momjian.us
EDB https://enterprisedb.com
Only you can decide what is important to you.
| Attachment | Content-Type | Size |
|---|---|---|
| txtime.diff | text/x-diff | 574 bytes |
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