Re: [HACKERS] What does it mean by XLOG_BACKUP_RECORD?

On Thu, Jun 29, 2017 at 10:28 AM, Masahiko Sawada <sawada.mshk@gmail.com> wrote:
> While reading source codes I found the following comment in xlog.c.
>
> /*
>  * Have we passed our safe starting point? Note that minRecoveryPoint is
>  * known to be incorrectly set if ControlFile->backupEndRequired, until
>  * the XLOG_BACKUP_RECORD arrives to advise us of the correct
>  * minRecoveryPoint. All we know prior to that is that we're not
>  * consistent yet.
>  */
> if (!reachedConsistency && !ControlFile->backupEndRequired &&
>     minRecoveryPoint <= lastReplayedEndRecPtr &&
>     XLogRecPtrIsInvalid(ControlFile->backupStartPoint))
>
> What does XLOG_BACKUP_RECORED means by? I could not find such XLOG info value.
> Does it mean XLOG_BACKUP_END?

This comment is a thinko, it refers to XLOG_BACKUP_END. This comment
block could be reworded a bit, it looks cleaner to me to say
"ControlFile->backupEndRequired is false" instead of just referring to
the variable itself. Worse, the current comment implies that
minRecoveryPoint is incorrectly set if it is true. Bleh.
-- 
Michael

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