Re: pg_last_xact_replay_timestamp meaning

On Fri, Mar 18, 2011 at 9:35 PM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> On Fri, Mar 18, 2011 at 7:23 PM, Bruce Momjian <bruce(at)momjian(dot)us> wrote:
>> I just applied a doc patch for pg_last_xact_replay_timestamp, and the
>> text now says:
>>
>>       <entry>Get timestamp of last transaction replayed during recovery.
>>        This is the time at which the commit or abort WAL record for that
>>        transaction was generated on the primary.
>>        If no transactions have been replayed during recovery, this function
>>        returns NULL.  Otherwise, if recovery is still in progress this will
>>        increase monotonically.  If recovery has completed then this value will
>>        remain static at the value of the last transaction applied during that
>>        recovery.  When the server has been started normally without recovery
>>        the function returns NULL.
>>
>> Is this really the last commit/abort record or the last WAL record?
>> What should it be?  Is the name of this function correct?  Do we care
>> only about commit/abort records? Why?
>
> Commit and abort records have a timestamp.  Other WAL records don't.

Incidentally, there's an open item related to this:

* pg_last_xact_replay_timestamp limitations
linking to http://archives.postgresql.org/message-id/201012071131.55211.gabi.julien@broadsign.com

I'm not sure why this is important enough to be worth being on this
list, but... is this resolved now?

--
Robert Haas
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