On 3/22/16 12:31 PM, Magnus Hagander wrote:
On Tue, Mar 22, 2016 at 5:27 PM, David Steele <da...@pgmasters.net <mailto:da...@pgmasters.net>> wrote:
>
> Adding the stop time column should be a simple addition and I don't see > a problem with that. I think I misunderstood your original request on > that. Because you are just talking about returning a timestamptz with > the "right now" value for when you called pg_stop_backup()? Or to be > specific, just before pg_Stop_backup *finished*. Or do you mean when > pg_stop_backup() started?What would be ideal is the minimum time that could be used for PITR. In an exclusive backup that's the time the end-of-backup record is written to WAL. In a non-exlusive backup I'm not quite sure how that works.
I guess I was hoping that you would know. I fine with just getting the current timestamp as is currently done in do_pg_stop_backup(). It's not perfect but it will be pretty close.
I thought some more about putting STOP_WAL_LOCATION into the backup label and I think this is an important step. Without that the recovery process needs to use pg_control to determine when the database has reach consistency and that will only work if pg_control was copied last.
In summary, I think the patch should be updated to include stop_time as a column and add STOP_WAL_LOCATION and STOP_TIME to backup_label. The recovery process should read STOP_WAL_LOCATION from backup_label and use that to decide when the database has become consistent.
Thanks, -- -David da...@pgmasters.net -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
