Tom Lane wrote:
>
> Justin Clift <justin@postgresql.org> writes:
> > Have been putting together a tool called "pg_autotune" for automatically
> > tuning a PostgreSQL database (either local or remote). It does this by
> > repetitively benchmarking PostgreSQL (using Tatsuo's pgbench code) with
> > different buffer settings, then fine tuning those settings depending on
> > the results returned.
>
> You should have chosen a better foundation. pg_bench is notorious for
> producing results that are (a) nonrepeatable and (b) not relevant to
> a wide variety of situations. All it really tells you about is the
> efficiency of a large number of updates to a small number of rows.
Hi Tom,
You're totally right about this. Have been forced to ensure that each
client connection does a minimum of 200 transactions per connection,
etc, just to get anything in the way of reliable results.
It's just that this started out as playing around with pgbench, then
grew from that. However, it's been put together so that other tests can
be added easily, and it doesn't even have to use Tatsuo's pgbench code.
Was thinking of asking Andy Riebs if we'd be ok to use his OSDB code, as
we'd need him to ok this in order to have it still be under the BSD
license.
> I'd take the results with a large grain of salt.
It takes the inaccuracy of Tatsuo's pgbench code into account.
:-)
Regards and best wishes,
Justin Clift
> regards, tom lane
--
"My grandfather once told me that there are two kinds of people: those
who work and those who take the credit. He told me to try to be in the
first group; there was less competition there."
- Indira Gandhi
