From: pgsql-hackers-ow...@postgresql.org > [mailto:pgsql-hackers-ow...@postgresql.org] On Behalf Of Michael Paquier > On Tue, Oct 24, 2017 at 5:58 PM, Tsunakawa, Takayuki > <tsunakawa.ta...@jp.fujitsu.com> wrote: > > If the latest checkpoint record is unreadable (the WAL > segment/block/record is corrupt?), recovery from the previous checkpoint > would also stop at the latest checkpoint. And we don't need to replay the > WAL records between the previous checkpoint and the latest one, because > their changes are already persisted when the latest checkpoint was taken. > So, the user should just do pg_resetxlog and start the database server when > the recovery cannot find the latest checkpoint record and PANICs? > > Not necessarily. If a failure is detected when reading the last checkpoint, > as you say recovery would begin at the checkpoint prior that and would stop > when reading the record of last checkpoint, still one could use a > recovery.conf with restore_command to fetch segments from a different > source, like a static archive, as only the local segment may be corrupted.
Oh, you are right. "If the crash recovery fails, perform recovery from backup." Anyway, I agree that the secondary checkpoint isn't necessary. Regards Takayuki Tsunakawa -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers