Re: Performance monitor

> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > How do people feel about adding a single handler to 7.1?  Is it
> > something I can slip into the current CVS, or will it have to exist as a
> > patch to 7.1.  Seems it would be pretty isolated unless someone sends
> > the signal, but it is clearly a feature addition.
> 
> > OK, I will distribute it as a patch.
> 
> Patch or otherwise, this approach seems totally unworkable.  A signal
> handler cannot do I/O safely, it cannot look at shared memory safely,
> it cannot even look at the backend's own internal state safely.  How's
> it going to do any useful status reporting?

Why can't we do what we do with Cancel, where we set a flag and check it
at safe places?

> Firing up a separate backend process that looks at shared memory seems
> like a more useful design in the long run.  That will mean exporting
> more per-backend status into shared memory, however, and that means that
> this is not a trivial change.

Right, that is a lot of work.

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