Jan Wieck <JanWieck@Yahoo.com> writes:
>>> bgwriter_delay = 50 (now default 200)
>>> bgwriter_percent = 2 (now default 1)
>>> bgwriter_maxpages = 200 (now default 100)
> Just what I was having the best TPC-C results with.
I'm a bit hesitant to reduce the default bgwriter_delay, since AFAICS
that will result in a direct increase in the CPU overhead incurred.
(It'd be nice if the bgwriter didn't have to scan through *all* the
buffers on every cycle ...)
If we keep the delay at 200 then the 50/2 numbers would be roughly
equivalent to 200/8, that is flush 8% every 200ms. I'm inclined to
propose 5% as the default bgwriter_percent --- what do you think?
We need not change the maxpages default since it wouldn't matter until
you had upwards of 2000 dirty buffers, which to me would indicate that
you had better be raising the other parameters anyway (and you could
never get there at all with the default shared_buffers setting).
regards, tom lane