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.