Re: Rename max_parallel_degree?

On 10/12/16 7:58 PM, Robert Haas wrote:
> I don't think it's wrong that the handling is done there, though.  The
> process that is registering the background worker is well-placed to
> check whether there are already too many, and if it does not then the
> slot is consumed at least temporarily even if it busts the cap.  On
> the flip side, the postmaster is the only process that is well-placed
> to know when a background worker terminates.  The worker process
> itself can't be made responsible for it, as you suggest below, because
> it may never even start up in the first place (e.g. fork() returns
> EAGAIN).  And the registering process can't be made responsible,
> because it might die before the worker.

Those are valid technical points.  I have not worked out any alternatives.

I'm concerned that all this makes background workers managed by
extensions second-class citizens.

-- 
Peter Eisentraut              http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services