On Sat, 20 Jun 2009, Simon Riggs wrote:
> I would suggest that we check how much WAL has been written. There may
> be a secondary effect or a different regression hidden in these results.
What's the easiest way to do that? My first thought was to issue a
checkpoint before the test (which is a good idea to make each test
consistent anyway), save the output from pg_controldata, test, checkpoint,
and look at the control data again. This seems kind of clunky though, but
still better than trolling through the OS statistics for the data. Any
clever ideas for a better way to measure bytes of WAL written during a
particular chunk of code? We may need some sort of checkpoint/sync after
the test to get correct results, because I've noticed that the tests I run
sometimes continue writing out buffers for a few seconds after the test
time is finished.
--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD