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 <br...@momjian.us> https://momjian.us
EDB https://enterprisedb.com
Only you can decide what is important to you.
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 93f068edcf..b311a11b33 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -25978,7 +25978,8 @@ SELECT collation for ('foo' COLLATE "de_DE");
They only provide useful data when the
<xref linkend="guc-track-commit-timestamp"/> configuration option is
enabled, and only for transactions that were committed after it was
- enabled.
+ enabled. The commit timestamps of frozen tuples are removed during
+ vacuum.
</para>
<table id="functions-commit-timestamp">
