Re: Postgresql performance degrading... how to diagnose the root cause

On Fri, Mar 29, 2013 at 8:31 AM, Franck Routier <franck(dot)routier(at)axege(dot)com>wrote:

> Hi,
>
> I don't know that tcp-b does
>>
> tpcb.jar is a java implementation of the http://www.tpc.org/tpcb/benchmark. It is not particularly representative of my workload, but gives
> a synthetic, db-agnostic, view of the system performance.
> We use it to have quick view to compare differents servers (different OS,
> different RDBMS, etc...).
>

I took a quick look at that implementation, and I can't make heads nor
tails of it. It is just a lit of .java files. There is no documentation,
README, instructions, or example usage. Am I missing something? How do I
run it, and tell it what scale to use and what database to connect to?

> That said, the test wil create tables, load them with data, and perform
> some transactions on them.
> The point that makes me wonder what happens, is that the test run on my
> main database is slow, while the same test run on a database on its own is
> quick.
> This is the same postgresql cluster (same postgresql.conf), same
> tablespace (so same disks), same hardware obviously.
>
> Regarding the server activity, it seems quite flat : iostat shows that
> disks are not working much (less than 5%),

Which column of the iostat output is that coming from?

> top shows only one active core, and load average is well under 1...
>

Can you show the first few rows of the top output?

Cheers,

Jeff