Re: Streaming Replication: Checkpoint_segment and wal_keep_segments on standby

Heikki Linnakangas <heikki.linnakangas@enterprisedb.com> writes:
> The central question is whether checkpoint_segments should trigger 
> restartpoints or not. When PITR and restartpoints were introduced, the 
> answer was "no", on the grounds that when you're doing recovery you're 
> presumably replaying the logs much faster than they were generated, and 
> you don't want to slow down the recovery by checkpointing too often.

> Now that we have bgwriter active during recovery, and streaming 
> replication which retains the streamed WALs so that we now risk running 
> out of disk space with long checkpoint_timeout, it's time to reconsider 
> that.

> I think we have three options:

What about

(4) pay some attention to the actual elapsed time since the last
restart point?

All the others seem like kluges that are relying on hard-wired rules
that are hoped to achieve something like a time-based checkpoint.
        regards, tom lane