Re: pg_dump & performance degradation

> It would be a bad idea to nice down a backend anyway, if the intent is
> to speed up other backends.  The Unix scheduler has no idea about
> application-level locking, so you'll get priority-inversion problems:
> once the nice'd backend has acquired any sort of lock, other backends
> that may be waiting for that lock are at the mercy of the low priority
> setting.  In effect, your entire database setup may be running at the
> nice'd priority relative to anything else on the system.
> 
> I think Philip's idea of adding some delays into pg_dump is a reasonable
> answer.  I'm just recommending a KISS approach to implementing the
> delay, in the absence of evidence that a more complex mechanism will
> actually buy anything...

I am worried about feature creep here.  Does any other database
implement this?  I can accept it as a config.h flag, but it seems
publishing it as a pg_dump flag is just way too complicated for users.

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
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