Re: Add checkpoint and redo LSN to LogCheckpointEnd log message

On Fri, Jan 28, 2022 at 11:16 AM Nathan Bossart
<nathandbossart(at)gmail(dot)com> wrote:
>
> I know I voted for "start=%X/%X, end=%X/%X," but looking at this again, I
> wonder if it could be misleading. "start" is the redo location, and "end"
> is the location of the checkpoint record, but I could understand why
> someone might think that "start" is the location of the previous checkpoint
> record and "end" is the redo location of the new one. I think your
> original idea of "lsn=%X/%X, redo lsn=%X/%X" could be a good alternative.
>
> Іn any case, this patch is small and otherwise looks reasonable to me, so I
> am going to mark it as ready-for-committer.

Thanks for your review. In summary, we have these options to choose
checkpoint LSN and last REDO LSN:

1) "start=%X/%X, end=%X/%X" (ControlFile->checkPointCopy.redo,
ControlFile->checkPoint)
2) "lsn=%X/%X, redo lsn=%X/%X"
3) "location=%X/%X, REDO location=%X/%X" -- similar to what
pg_controldata and pg_control_checkpoint shows currently.
4) "location=%X/%X, REDO start location=%X/%X"

I will leave that decision to the committer.

Regards,
Bharath Rupireddy.