Re: stats collector suddenly causing lots of IO

Josh Kupershmidt  writes:
>         name         | current_setting |       source
> ----------------------+-----------------+--------------------
>  vacuum_cost_delay    | 200ms           | configuration file
>  vacuum_cost_limit    | 100             | configuration file
>  vacuum_cost_page_hit | 6               | configuration file
> 
> It looks like the default which I have of autovacuum_vacuum_cost_limit
> = -1, which means it's inheriting the vacuum_cost_limit of 100 I had
> set. I'll try bumping vacuum_cost_limit up to 1000 or so.

Actually I think the main problem is that cost_delay value, which is
probably an order of magnitude too high.  The way to limit vacuum's
I/O impact on other stuff is to make it take frequent short delays,
not have it run full speed and then sleep a long time.  In any case,
your current settings have got it sleeping way too much.  Two WEEKS !!!??

			regards, tom lane