On Thu, Jan 5, 2012 at 2:25 PM, Robert Haas <robertmhaas@gmail.com> wrote:
> On Thu, Jan 5, 2012 at 2:44 PM, Kevin Grittner
> <Kevin.Grittner@wicourts.gov> wrote:
>> If we go with such a formula, I think 32 MB would be a more
>> appropriate divisor than 128 MB. Even on very large machines where
>> 32 CLOG buffers would be a clear win, we often can't go above 1 or 2
>> GB of shared_buffers without hitting latency spikes due to overrun
>> of the RAID controller cache. (Now, that may change if we get DW
>> in, but that's not there yet.) 1 GB / 32 is 32 MB. This would
>> leave CLOG pinned at the minimum of 8 buffers (64 KB) all the way up
>> to shared_buffers of 256 MB.
>
> That seems reasonable to me.
likewise (champion bikeshedder here). It just so happens I typically
set 'large' server shared memory to 256mb.
merlin