Re: Sampling Profler for Postgres

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

> Compiled and Works fine here on Ubuntu 8.04 2.6.25.15-bd-mod #1 SMP
> PREEMPT Thu Nov 27 10:05:44 BRST 2008 i686 GNU/Linux

Thanks for testing. Network (or communication between pgbench and postgres)
seems to be a bottleneck on your machine.

> Two questions here:
>
> 1) How will be this behavior in a syncrep environment? I don't have one
> here to test this, yet.

I think it has relation with hot-standby, but not syncrep.
Profiling is enabled when stats collector process is running.
We already run the collector during warm-standby, so profiling would
be also available on log-shipping slaves.

> 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.

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