On 2022/02/14 14:40, Kyotaro Horiguchi wrote:
For backbranches, the attached for pg14 does part of the full patch.
Thanks for updating the patch!
Of the following, I think we should do (a) and (b) to make future
backpatchings easier.
a) Use RedoRecPtr and PriorRedoPtr after they are assigned.
b) Move assignment to PriorRedoPtr into the ControlFileLock section.
I failed to understand how (a) and (b) can make the backpatching easier. How
easy to backpatch seems the same whether we apply (a) and (b) or not...
c) Skip udpate of minRecoveryPoint only when the checkpoint gets old.
Yes.
d) Skip call to UpdateCheckPointDistanceEstimate() when RedoRecPtr <=
PriorRedoPtr.
But "RedoRecPtr <= PriorRedoPtr" will never happen, will it? Because a restartpoint is
skipped at the beginning of CreateRestartPoint() in that case. If this understanding is right, the check
of "RedoRecPtr <= PriorRedoPtr" is not necessary before calling
UpdateCheckPointDistanceEstimate().
+ ControlFile->minRecoveryPoint = InvalidXLogRecPtr;
+ ControlFile->minRecoveryPointTLI = 0;
Don't we need to update LocalMinRecoveryPoint and LocalMinRecoveryPointTLI
after this? Maybe it's not necessary, but ISTM that it's safer and better to
always update them whether the state is DB_IN_ARCHIVE_RECOVERY or not.
if (flags & CHECKPOINT_IS_SHUTDOWN)
ControlFile->state = DB_SHUTDOWNED_IN_RECOVERY;
Same as above. IMO it's safer and better to always update the state (whether
the state is DB_IN_ARCHIVE_RECOVERY or not) if CHECKPOINT_IS_SHUTDOWN flag is
passed.
Regards,
--
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION
