Re: replication optimization: page writes only at the slave

On Mon, Dec 10, 2012 at 10:56 AM, Xin Pan <panxin0718(at)gmail(dot)com> wrote:
> However, I still witness large amount of page writes.
> Can anyone tell where are the page writes come from?

Probably not without more details. Things like VACUUM, COPY, and
sequential scans use ring-buffers that are smaller than
shared_buffers, so you often see the cache fill up with your data only
slowly just after starting the database, but if the database really
fits in shared_buffers, you should eventually settle into a rhythm
where dirty buffers are written to disk only once per checkpoint
cycle.

You might want to monitor pg_stat_bgwriter.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company