On Wed, Jan 4, 2012 at 11:02 AM, Simon Riggs <[email protected]> wrote: > On Wed, Jan 4, 2012 at 3:56 PM, Heikki Linnakangas > <[email protected]> wrote: >> On 04.01.2012 08:42, Amit Kapila wrote: >>> >>> Why PostgreSQL needs to write WAL record for Checkpoint when it maintains >>> same information in pg_control file? >> >> >> I guess it wouldn't be strictly necessary... > > Apart from replicated standbys, which need that info for running > restartpoints.
Yeah. But, the OP makes me wonder: why can a standby only perform a restartpoint where the master performed a checkpoint? It seems like a standby ought to be able to create a restartpoint anywhere, just by writing everything, flushing it to disk, and update pg_control. I assume there's some reason that doesn't work, I just don't know what it is... -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list ([email protected]) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
