Re: Sampling Profler for Postgres

"Dickson S. Guedes" <listas(at)guedesoft(dot)net> wrote:

> > > 2) I couldn't find a clear way to disable it. There is one in this patch
> > > or are you planning this to future?
> >
> > Ah, I forgot sampling should be disabled when track_activities is off.
> > I'll fix it in the next patch. Also, I'd better measure overheads
> > by the patch.
>
> Will be very nice if I could on/off it. When done, please send us. I'd
> like to test it in some stress scenarios, enabling and disabling it on
> some environment and comparing with my old benchmarks.

Here is a new version of the patch. I added a new GUC parameter
'profiling_interval' (ms). Profiling is disabled when the value is 0.
The default value is 1 second. You could get more granular results
if you set the value to 100-500ms, but 1 sec should be enough for
continuous regular load (like benchmarks).

I cannot see any differences whether profiling is on/off.
So I think sampling has little overheads for now.
Please notify me report if you see troubles.

Regards,
---
ITAGAKI Takahiro
NTT Open Source Software Center