Re: Remove secondary checkpoint

On Mon, Oct 30, 2017 at 2:22 PM, Simon Riggs <simon(at)2ndquadrant(dot)com> wrote:
> On 25 October 2017 at 00:17, Michael Paquier <michael(dot)paquier(at)gmail(dot)com> wrote:
>> - * Delete old log files (those no longer needed even for previous
>> - * checkpoint or the standbys in XLOG streaming).
>> + * Delete old log files and recycle them
>> */
>> Here that's more "Delete or recycle old log files". Recycling of a WAL
>> segment is its renaming into a newer segment.
>
> Sometimes files are deleted if there are too many.

Sure, but one segment is never deleted and then recycled, which is
what your new comment implies as I understand it.

>> - checkPointLoc = ControlFile->prevCheckPoint;
>> + /*
>> + * It appears to be a bug that we used to use
>> prevCheckpoint here
>> + */
>> + checkPointLoc = ControlFile->checkPoint;
>> Er, no. This is correct because we expect the prior checkpoint to
>> still be present in the event of a failure detecting the latest
>> checkpoint.
>
> I'm removing "prevCheckPoint", so not sure what you mean.

I mean that there is no actual bug here. And changing the code as you
do is correct, but the comment is not.
--
Michael