On Mon, Apr 25, 2016 at 12:17:56PM +0200, Magnus Hagander wrote: > > > On Mon, Apr 25, 2016 at 5:01 AM, Robert Haas <robertmh...@gmail.com> wrote: > > On Sun, Apr 24, 2016 at 2:42 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > > Magnus Hagander <mag...@hagander.net> writes: > >> On Sun, Apr 24, 2016 at 8:23 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > >>> FWIW, I agree with Bruce that using "degree" here is a poor choice. > >>> It's an unnecessary dependence on technical terminology that many > people > >>> will not be familiar with. > > > >> FWIW, SQL Server calls it "degree of parallelism" as well ( > >> https://technet.microsoft.com/en-us/library/ms188611(v=sql.105).aspx). > And > >> their configuration option is "max degree of parallelism": > >> https://technet.microsoft.com/en-us/library/ms181007(v=sql.105).aspx. > > > > Yes, but both they and Oracle appear to consider "degree" to mean the > > total number of processors used, not the number of secondary jobs in > > addition to the main one. The only thing worse than employing obscure > > technical terminology is employing it incorrectly: that way, you get to > > confuse both the users who know what it means and those who don't. > > This is not so clear-cut as you are making it out to be. For example, > see http://www.akadia.com/services/ora_parallel_processing.html - viz > "The number of parallel slave processes associated with an operation > is called its degree of parallelism", which is pretty close to what > the parameter currently called max_parallel_degree actually does. > > > > So maybe something like session_parallel_degree, to add another color to the > bikeshed?
I think Robert said it is per-executor node, not per session, similar to work_mem. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + As you are, so once was I. As I am, so you will be. + + Ancient Roman grave inscription + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
