Re: SSDs with Postgresql?

On Thursday, April 21, 2011 8:33:45 am Florian Weimer wrote:
> * Greg Smith:
> > The fact that every row update can temporarily use more than 8K means
> > that actual write throughput on the WAL can be shockingly large.  The
> > smallest customer I work with regularly has a 50GB database, yet they
> > write 20GB of WAL every day.  You can imagine how much WAL is
> > generated daily on systems with terabyte databases.
>
> Interesting.  Is there an easy way to monitor WAL traffic in away?  It
> does not have to be finegrained, but it might be helpful to know if
> we're doing 10 GB, 100 GB or 1 TB of WAL traffic on a particular
> database, should the question of SSDs ever come up.

They are found in $DATA/pg_xlog so checking the size of that directory regularly
would get you the information.


--
Adrian Klaver
adrian.klaver@gmail.com