Re: 8.2 is 30% better in pgbench than 8.3

On Jul 22, 2007, at 8:54 AM, Josh Berkus wrote:
> Tom,
>> Note to all: we ***HAVE TO*** settle on some reasonable default
>> vacuum_cost_delay settings before we can ship 8.3.  With no cost  
>> delay
>> and two or three workers active, 8.3's autovac does indeed send
>> performance into the tank.
>
> I've been using 20ms for most of my setups.  That's aimed at  
> reducing autovac to almost no impact at all, but taking a long  
> time.  Maybe 10ms?

I've found 20ms to be a pretty good number for run-of-the-mill IO  
capability, and 10ms to be good for a good RAID setup (RAID10, 8+  
drives, BBU).

For a default setting, I think it'd be better to lean towards 20ms.
--
Jim Nasby                                            jim@nasby.net
EnterpriseDB      http://enterprisedb.com      512.569.9461 (cell)