On 02/18/2014 10:51 PM, Andres Freund wrote:
> On 2014-02-18 19:12:32 +0200, Heikki Linnakangas wrote:
>> Yeah, I'm pretty sure that's because of the extra checkpoints. If you look
>> at the individual test graphs, there are clear spikes in latency, but the
>> latency is otherwise small. With a higher TPS, you reach checkpoint_segments
>> quicker; I should've eliminated that effect in the tests I ran...
>
> I don't think that'd be a good idea. The number of full page writes so
> greatly influences the WAL charactersistics, that changing checkpoint
> segments would make the tests much harder to compare.
I was just thinking of bumping up checkpoint_segments so high that there
are no checkpoints during any of the tests.
- Heikki
