Re: a heavy duty operation on an "unused" table kills my server

Eduardo Piombino wrote:
> In the case where priority inversion is not to be used, I would
> however still greatly benefit from the slow jobs/fast jobs mechanism,
> just being extra-careful that the slow jobs, obviously, did not
> acquire any locks that a fast job would ever require. This alone would
> be, still, a *huge* feature if it was ever to be introduced,
> reinforcing the real-time awareness/requirements, that many
> applications look for  today.

In this context, "priority inversion" is not a generic term related to
running things with lower priorities.  It means something very
specific:  that you're allowing low-priority jobs to acquire locks on
resources needed by high-priority ones, and therefore blocking the
high-priority ones from running effectively.  Unfortunately, much like
deadlock, it's impossible to avoid the problem in a generic way just by
being careful.  It's one of the harder issues that needs to be
considered in order to make progress on implementing this feature one day.

--
Greg Smith    2ndQuadrant   Baltimore, MD
PostgreSQL Training, Services and Support
greg@2ndQuadrant.com  www.2ndQuadrant.com