C?dric Villemain wrote: > 2010/11/25 Bruce Momjian <br...@momjian.us>: > > Document that a CHECKPOINT before taking a file system snapshot can > > reduce recovery time. > > I didn't follow that on -hackers, but : > > * checkpoint take place in the pg_start_backup process (before it > releases the hand, so before you can start snapshoting) > > * we used to issue a checkpoint *before* pg_start_backup to reduce > pg_start_backup duration in case you have wal_archiving turn off and > full_page_write is off, it reduces a bit the IO contention. (or even > if not I hate seing this pg_start_backup taking seconds/minutes to > finish) > > How the checkpoint before will reduce recovery time ?
This is for using file system snapshots, not PITR or continuous archiving. The checkpoint reduces how much WAL has to be replayed. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + It's impossible for everything to be true. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
