Re: clog_buffers to 64 in 8.3?

On Thu, 2 Aug 2007, Tom Lane wrote:

> I find it entirely likely that simply changing the [NUM_CLOG_BUFFERS] 
> constant would be a net loss on many workloads.

Would it be reasonable to consider changing it to a compile-time option 
before the 8.3 beta?  From how you describe the potential downsides, it 
sounds to me like something that specific distributors might want to 
adjust based on their target customer workloads and server scale.  That 
would make it available as a tunable to those aiming at larger systems 
with enough CPU/memory throughput that the additional overhead of more 
linear searches is trumped by the reduced potential for locking 
contention, as appears to be the case in Sun's situation here.

--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD