On 1/18/17 8:25 AM, Stephen Frost wrote: > I was actually thinking about it the other way- start out by changing > them to both be 5m and then document next to checkpoint_timeout (and > max_wal_size, perhaps...) that if you go changing those parameters (eg: > bumping up checkpoint_timeout to 30 minutes and max_wal_size up enough > that you're still checkpointing based on time and not due to running out > of WAL space) then you might need to consider raising the timeout for > pg_ctl to wait around for the server to finish going through crash > recovery due to all of the outstanding changes since the last > checkpoint.
It is important for users to be aware of this, but I don't think the relationship between checkpoint_timeout and recovery time is linear, so it's unclear what the exact advice should be. Personally, I think the timeout in pg_ctl is wrong and needs to be disabled in practical applications, but that is a different discussion. -- Peter Eisentraut http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
