Re: Just-in-time Background Writer Patch+Test Results

Greg Smith <gsmith(at)gregsmith(dot)com> writes:
> If anyone has a reason why they feel the bgwriter_delay needs to be a
> tunable or why the rate might need to run even faster than 10ms, now would
> be a good time to say why.

You'd be hard-wiring the thing to wake up 100 times per second? Doesn't
sound like a good plan from here. Keep in mind that not everyone wants
their machine to be dedicated to Postgres, and some people even would
like their CPU to go to sleep now and again.

I've already gotten flak about the current default of 200ms:
https://bugzilla.redhat.com/show_bug.cgi?id=252129
I can't imagine that folk with those types of goals will tolerate
an un-tunable 10ms cycle.

In fact, given the numbers you show here, I'd say you should leave the
default cycle time at 200ms. The 10ms value is eating way more CPU and
producing absolutely no measured benefit relative to 200ms...

regards, tom lane