Re: [PATCH] Expose checkpoint reason to completion log messages.

Hi all,

Thank you for the review and feedback for raising these points.
While the checkpoint starting message already includes the reason, in
practice the checkpoint completion message is what users most often
look at for performance analysis since it contains the detailed
timing, buffer, and WAL statistics to refer to. When extracting or
aggregating logs, it is currently necessary to correlate the
completion message back to the corresponding starting message to
determine the checkpoint type, which is not always convenient or
reliable in busy systems. Including the reason directly in the
completion message avoids that extra step.
I agree with your point that the checkpoint completion message should
use the same terminology as the starting message ( “fast” rather than
“immediate”) and I have updated the patch accordingly and have
attached herewith for review. This patch aligns the checkpoint
completion log wording with the existing checkpoint starting message
(using “fast” instead of “immediate”) for consistency.
And regarding why this information has historically only been present
in the starting message, I think the completion log originally focused
purely on reporting I/O and timing statistics, rather than contextual
metadata. With the increasing use of log analysis for performance
troubleshooting, it is reasonable to include the checkpoint reason
with those statistics for the detailed analysis.
Kindly review my patch and let me know the feedback.

Regards,
Soumya