Re: Rename max_parallel_degree? - Mailing list pgsql-hackers

From Magnus Hagander
Subject Re: Rename max_parallel_degree?
Date
Msg-id CABUevEzzvdu9WHmfyMxyW0pY-JhF=bKA88NMnhuAeROoi_vGag@mail.gmail.com
Whole thread Raw
In response to Re: Rename max_parallel_degree?  (Robert Haas <robertmhaas@gmail.com>)
Responses Re: Rename max_parallel_degree?  (Bruce Momjian <bruce@momjian.us>)
List pgsql-hackers


On Mon, Apr 25, 2016 at 5:01 AM, Robert Haas <robertmhaas@gmail.com> wrote:
On Sun, Apr 24, 2016 at 2:42 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Magnus Hagander <magnus@hagander.net> writes:
>> On Sun, Apr 24, 2016 at 8:23 PM, Tom Lane <tgl@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?


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