Re: Linux max on shared buffers?

On Wed, 10 Jul 2002, Bruce Momjian wrote:

> Woh, 10MB is clearly too low.  Remember, there is copying overhead of
> moving data from the kernel to the PostgreSQL shared buffers.

Yes, but the cost of copying between a postgres buffer and an OS buffer
is much, much less than the cost of copying between an OS buffer and disk.

However, it all depends on your working set, doesn't it? So I can't make
a strong argument either way. What do you think is better? 20 MB? 100
MB? Do you allocate based on the number of connections, or a proportion
of the machine's memory, or something else? I was estimating based on
the number of connections.

cjs
--
Curt Sampson  <cjs@cynic.net>   +81 90 7737 2974   http://www.netbsd.org
    Don't you know, in this new Dark Age, we're all light.  --XTC