Re: [RFC] obtaining the function call stack

Tom Lane wrote:
> Alvaro Herrera <alvherre@commandprompt.com> writes:
> > So, the idea is to have a stack maintained by the function manager; each
> > called function enters an element in it containing the interesting
> > information about the function.  We'd have another function that would
> > return this stack as a result set.  (With this arrangement, the topmost
> > element would always appear to be this "peek" function.)
> 
> > I haven't looked at the code to see how this would actually be
> > implemented, so I don't have more details to offer.  Does anybody have
> > opinions on the matter?
> 
> The performance and error recovery implications are unfavorable.
> Just how badly do you need this, and for what?

Mainly for debugging.  The situation is such that there is a lot of
functions and very high load.  The functions have embedded "debug elogs"
and the intention is to call them only if the function was called in a
particular context.

I think error recovery would just have to be done carefully.  As for
performance, maybe the feature could be turned on with a (ugh) GUC
variable, and defaults to off.

-- 
Alvaro Herrera                                http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.