On Thu, Apr 21, 2011 at 10:33 AM, Florian Weimer <fweimer@xxxxxx> wrote:
If you archive your WAL files, wouldn't that give you a pretty good indication of write activity?* Greg Smith:
Interesting. Is there an easy way to monitor WAL traffic in away? It
> 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.
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.
For example, yesterday I archived 74 WAL files, each 16MB. That's about 1.2 gigabytes for a database that takes up about 58 GB.
--
Mike Nolan
