On Fri, Jun 22, 2018 at 05:21:32PM +0900, Kyotaro HORIGUCHI wrote: > Hello. > > I don't find any description in the documentation about the > guaranteed lifetime of commit timestamps. I think they are > preserved until corresponding xid goes beyond the freeze horizen, > even though they are actually preserved longer for several > reasons. > > If it is not, I think such description is required in > pg_xact_commit_timestamp().
> diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml > index 5dce8ef178..633e488cec 100644 > --- a/doc/src/sgml/func.sgml > +++ b/doc/src/sgml/func.sgml > @@ -18029,7 +18029,8 @@ SELECT collation for ('foo' COLLATE "de_DE"); > These functions mainly provide information about when the transactions > were committed. They only provide useful data when > <xref linkend="guc-track-commit-timestamp"/> configuration option is > enabled > - and only for transactions that were committed after it was enabled. > + and only for transactions that were committed after it was enabled. > Commit > + timestamps for frozen tuples are removed at vacuum time. > </para> Is this documentation change still relevant? -- Bruce Momjian <br...@momjian.us> https://momjian.us EDB https://enterprisedb.com Only you can decide what is important to you.