Re: [HACKERS] max_parallel_degree context level

2016-03-21 Thread Robert Haas
On Sun, Mar 20, 2016 at 3:01 AM, David Rowley wrote: > On 12 February 2016 at 04:55, Robert Haas wrote: >> On Thu, Feb 11, 2016 at 10:32 AM, Simon Riggs wrote: >>> Is it slower if you request N workers, yet only 1 is available? >> >> I sure hope so. There may be some cases where more workers ar

Re: [HACKERS] max_parallel_degree context level

2016-03-20 Thread David Rowley
On 12 February 2016 at 04:55, Robert Haas wrote: > On Thu, Feb 11, 2016 at 10:32 AM, Simon Riggs wrote: >> Is it slower if you request N workers, yet only 1 is available? > > I sure hope so. There may be some cases where more workers are slower > than fewer workers, but those cases are defects t

Re: [HACKERS] max_parallel_degree context level

2016-02-11 Thread Joe Conway
On 02/11/2016 07:55 AM, Robert Haas wrote: > On Thu, Feb 11, 2016 at 10:32 AM, Simon Riggs 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

Re: [HACKERS] max_parallel_degree context level

2016-02-11 Thread Robert Haas
On Thu, Feb 11, 2016 at 10:32 AM, Simon Riggs wrote: > A few questions and thoughts to help decide... > > Does it take into account the parallel degree during planning? > Does it take into account the actual parallel degree during planning? max_worker_processes is a query planner GUC, just like w

Re: [HACKERS] max_parallel_degree context level

2016-02-11 Thread Simon Riggs
On 11 February 2016 at 12:40, Thom Brown wrote: > Hi all, > > As it currently stands, max_parallel_degree is set to a superuser > context, but we probably want to discuss whether we want to keep it > this way prior to releasing 9.6. Might we want to reduce its level so > that users can adjust it

Re: [HACKERS] max_parallel_degree context level

2016-02-11 Thread Dean Rasheed
On 11 February 2016 at 13:18, Robert Haas wrote: > On Thu, Feb 11, 2016 at 7:40 AM, Thom Brown wrote: >> As it currently stands, max_parallel_degree is set to a superuser >> context > > I don't have a clue why it's like that. It seems like it should be > PGC_USERSSET just like, say, work_mem. I

Re: [HACKERS] max_parallel_degree context level

2016-02-11 Thread Robert Haas
On Thu, Feb 11, 2016 at 7:40 AM, Thom Brown wrote: > As it currently stands, max_parallel_degree is set to a superuser > context, but we probably want to discuss whether we want to keep it > this way prior to releasing 9.6. Might we want to reduce its level so > that users can adjust it according

[HACKERS] max_parallel_degree context level

2016-02-11 Thread Thom Brown
Hi all, As it currently stands, max_parallel_degree is set to a superuser context, but we probably want to discuss whether we want to keep it this way prior to releasing 9.6. Might we want to reduce its level so that users can adjust it accordingly? They'd still be limited by max_worker_processe