On Thu, 12 Jan 2006, Jim C. Nasby wrote:
>
> It sounds like worrying about this would be much more interesting on a
> machine that is seeing both a fairly heavy IO load (meaning checkpoint
> will both take longer and affect other workloads more) and is seeing a
> pretty high rate of buffer updates (meaning that we'd likely do a bunch
> of extra work as part of the checkpoint if we didn't take note of
> exactly what buffers needed to be flushed). Unfortunately I don't think
> there's any way for the backend to know much about either condition
> right now, so it couldn't decide when it made sense to make a list of
> buffers to flush. Maybe in the future...
>
The senario you mentioned is happened in many OLTP applications. No need
for backend to know this -- we can leave the decision to the DBA:
CHECKPOINT FULL or CHECPOINT PARTIAL. If you got some machines can observe
its CHECKPOINT duration, that would be sweet.
Regards,
Qingqing