On Thu, Apr 21, 2011 at 10:33 AM, Florian Weimer <fwei...@bfk.de> 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. > > If you archive your WAL files, wouldn't that give you a pretty good indication of write activity? 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
