Re: max_parallel_degree context level

On 02/11/2016 07:55 AM, Robert Haas wrote:
> On Thu, Feb 11, 2016 at 10:32 AM, Simon Riggs <simon(at)2ndquadrant(dot)com> wrote:
>> If you make max_worker_processes USERSET won't everybody just set it to
>> max_worker_processes?
>
> I think that you meant for the first instance of max_worker_processes
> in that sentence to be max_parallel_degree. I'll respond as if that's
> what you meant. Basically, I think this like asking whether everybody
> won't just set work_mem to the entire amount of free memory on the
> machine and try to use it all themselves. We really have never tried
> very hard to prevent that sort of thing in PostgreSQL. Maybe we
> should, but we'd have to fix an awful lot of stuff. There are many
> ways for malicious users to do things that interfere with the ability
> of other users to use the system. I admit that the same problem
> exists here, but I don't think it's any more severe than any of the
> cases that already exist. In some ways I think it's a whole lot LESS
> serious than what a bad work_mem setting an do to your system.

This is pretty much exactly what I was thinking -- work_mem is already a
bigger potential problem than this. In general I think we need to
eventually provide more admin control over USERSET GUCs, but that is a
whole other conversation.

Joe

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