On Sat, Mar 31, 2012 at 8:31 PM, Peter Geoghegan <peter(at)2ndquadrant(dot)com> wrote:
> The exact benchmark that I ran was the update.sql pgbench-tools
> benchmark, on my laptop. The idea was to produce a sympathetic
> benchmark with a workload that was maximally commit-bound. Heikki
> reproduced similar numbers on his laptop, iirc. Presumably the default
> TPC-B-like transaction test has been used here.
OK, I ran pgbench-tools with your configuration file. Graphs
attached. Configuration otherwise as in my standard pgbench runs,
except max_connections=1000 to accommodate the needs of the test. I
now see the roughly order-of-magnitude increase you measured earlier.
There seem to be too relevant differences between your test and mine:
(1) your test is just a single insert per transaction, whereas mine is
pgbench's usual update, select, update, update, insert and (2) it
seems that, to really see the benefit of this patch, you need to pound
the server with a very large number of clients. On this test, 250
clients was the sweet spot.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
