Re: Streaming Replication: Checkpoint_segment and wal_keep_segments on standby

Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)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