Re: Let PostgreSQL's On Schedule checkpoint write buffer smooth spread cycle by tuning IsCheckpointOnSchedule?

> You don't have to do anything if you don't want to.

Sure:-) What I mean is that I think that this patch is not ripe, and I 
understood that some people were suggesting that it could be applied as is 
right away. I'm really disagreeing with that.

> I said myself that this needs performance testing of the worst-case 
> scenario, one where we would expect this to perform worse than without 
> the patch. Then we can look at how bad that effect is, and decide if 
> that's acceptable.

Ok, I'm fine with that. It's quite different from "looks ok apply now".

> That said, if you could do that testing, that would be great!

Hmmm. I was not really planing to. On the other hand, I have some scripts 
and a small setup that I've been using to test checkpointer flushing, and 
it would be easy to start some tests.

>> Having a guc would also help to test the feature with different values
>> than 1.5, which really seems harmful from a math point of view. I'm not
>> sure at all that a power formula is the right approach.
>
> Yeah, a GUC would be helpful in testing this. I'm hoping that we would come 
> up with a reasonable formula that would work well enough for everyone that we 
> wouldn't need to have a GUC in the final patch, though.

Yep. If it is a guc testing is quite easy and I may run my scripts...

-- 
Fabien.