Re: Controlling Load Distributed Checkpoints

Heikki Linnakangas <heikki@enterprisedb.com> writes:
> GUC summary and suggested default values
> ----------------------------------------
> checkpoint_write_percent = 50         # % of checkpoint interval to spread out 
> writes
> checkpoint_write_min_rate = 1000    # minimum I/O rate to write dirty 
> buffers at checkpoint (KB/s)
> checkpoint_nap_duration = 2         # delay between write and sync phase, in 
> seconds
> checkpoint_fsync_period = 30        # duration of the sync phase, in seconds
> checkpoint_fsync_delay = 500        # max. delay between fsyncs

> I don't like adding that many GUC variables, but I don't really see a 
> way to tune them automatically.

If we don't know how to tune them, how will the users know?  Having to
add that many variables to control one feature says to me that we don't
understand the feature.

Perhaps what we need is to think about how it can auto-tune itself.
        regards, tom lane