Обсуждение: 'postmaster -B [nBuffers]'

The default for disk buffers number is 64. I think it's not big enough.
If my box has 128 or 256 MB RAM, what's the percentage of RAM should be
assigned to postmaster by using '-B' option? Any experience about the
performence regarding to the change of buffer size?

Thanks!

Jack Zhu wrote:
>
> The default for disk buffers number is 64. I think it's not big enough.
> If my box has 128 or 256 MB RAM, what's the percentage of RAM should be
> assigned to postmaster by using '-B' option? Any experience about the
> performence regarding to the change of buffer size?


Try this:  Run the "top" display and watch the CPU utilization.
Add buffers and/or more physical RAM untill your Postgresql
server becomes CPU bound.  You can tell if it is when the
utilization is close to 100%.  If the CPU utilization is low
it means the CPU is waiting on the disk.

A direct answer is "B = a few thousand"

   --Chris Albertson             home: chrisja@jps.net
     Redondo Beach, California   work: calbertson@logicon.com