On Feb 22, 2010, at 6:47 PM, Greg Smith wrote:
Ben Chobot wrote:
Is it reading it correctly to say that the bgwriter probably wouldn't help
much, because a majority of the dirty pages appear to be popular?
Yes. The background writer cleaner process only does something useful if
there
Ben Chobot wrote:
Hm, my shared_buffers is already 10GB, but I'm using about 80GB for filesystem
cache. Would a larger shared_buffers make sense? I thought I read somewhere
that 10GB is on the high end of the useful size for shared_buffers.
Yeah, I figured that out when I was analyzing your
On Feb 17, 2010, at 6:38 PM, Greg Smith wrote:
Ben Chobot wrote:
Is there a way to tell if I really am just keeping the same few pages dirty
throughout every checkpoint? I wouldn't have expected that, but given our
application I suppose it is possible.
You can install pg_buffercache and
Ben Chobot wrote:
Is it reading it correctly to say that the bgwriter probably wouldn't
help much, because a majority of the dirty pages appear to be popular?
Yes. The background writer cleaner process only does something useful
if there are pages with low usage counts it can evict. You
Ben Chobot wrote:
As I understand things, assuming I don't keep updating the same pages
then buffers_backend should be a small percentage of buffers_alloc,
and buffers_clean should be larger than it is compared to
buffers_checkpoint. Is my understanding correct?
Sure; your buffers_clean is
On Feb 17, 2010, at 3:41 PM, Greg Smith wrote:
Ben Chobot wrote:
As I understand things, assuming I don't keep updating the same pages then
buffers_backend should be a small percentage of buffers_alloc, and
buffers_clean should be larger than it is compared to buffers_checkpoint. Is
my
Ben Chobot wrote:
Is there a way to tell if I really am just keeping the same few pages dirty
throughout every checkpoint? I wouldn't have expected that, but given our
application I suppose it is possible.
You can install pg_buffercache and look at what's in the cache to check
your theory.
We recently upgraded to 8.4.2 and I'm trying to make sure our bgwriter is
working as well as it can. Based on:
# select * from pg_stat_bgwriter ;
checkpoints_timed | checkpoints_req | buffers_checkpoint | buffers_clean |
maxwritten_clean | buffers_backend | buffers_alloc
On Feb 14, 2010, at 10:25 AM, Ben Chobot wrote:
We recently upgraded to 8.4.2 and I'm trying to make sure our bgwriter is
working as well as it can. Based on:
# select * from pg_stat_bgwriter ;
checkpoints_timed | checkpoints_req | buffers_checkpoint | buffers_clean |
maxwritten_clean |
