Re: some longer, larger pgbench tests with various performance-related patches

On Tue, Jan 24, 2012 at 12:53 PM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> Early yesterday morning, I was able to use Nate Boley's test machine
> do a single 30-minute pgbench run at scale factor 300 using a variety
> of trees built with various patches, and with the -l option added to
> track latency on a per-transaction basis.  All tests were done using
> 32 clients and permanent tables.  The configuration was otherwise
> identical to that described here:
>
> http://archives.postgresql.org/message-id/CA+TgmoboYJurJEOB22Wp9RECMSEYGNyHDVFv5yisvERqFw=6dw@mail.gmail.com

Previously we mostly used this machine for CPU benchmarking. Have you
previously described the IO subsystem? That is becoming relevant for
these types of benchmarks. For example, is WAL separated from data?

>
> By doing this, I hoped to get a better understanding of (1) the
> effects of a scale factor too large to fit in shared_buffers,

In my hands, the active part of data at scale of 300 fits very
comfortably into 8GB shared_buffers.

Indeed, until you have run a very long time so that pgbench_history
gets large, everything fits in 8GB.

Cheers,

Jeff