Re: Rename max_parallel_degree?

On Tue, Apr 26, 2016 at 11:49 AM, Robert Haas <robertmhaas@gmail.com> wrote:
> On Tue, Apr 26, 2016 at 11:44 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Robert Haas <robertmhaas@gmail.com> writes:
>>> I still think
>>> max_parallel_workers is confusingly similar to max_worker_processes,
>>> but nothing's going to make everyone completely happy here.
>>
>> Well, what was suggested upthread was to change all of these to follow
>> the pattern max_foo_workers or max_foo_worker_processes, where foo would
>> (hopefully) clarify the scope in which the limitation applies.
>
> Well, I don't like max_node_parallel_degree much.  We don't call it
> max_node_work_mem.  And node is not exactly a term that's going to be
> more familiar to the average PostgreSQL user than parallel degree is
> to (apparently) the average PostgreSQL developer.  I think at some
> point adding noise words hurts more than it helps, and you've just got
> to ask people to RTFM if they really want to understand.

If we're going to change this before beta1, we need to do it soon.
IMHO, the only reasonably sane idea that's been proposed thus far is
to rename as follows:

max_parallel_degree -> max_parallel_workers
parallel_degree -> parallel_workers

I would prefer to keep it as "degree".  It's a reasonable term of art,
and it also improves grep-ability.  But I'm willing to go do the above
renaming if there is a clear consensus behind it.  Alternatively, I'm
willing to make it 1-based rather than 0-based if there is a clear
consensus on that option, though unsurprisingly I prefer it the way it
is now.  Do we have such a consensus?

To summarize the positions as I understand them:

Magnus seems OK with the way things are.
Peter wants to change either the fact that it is 0-based or the fact
that it is called degree, but is OK with either.
Tom doesn't like "degree" and also thinks anything called degree
should 1-based, but it sounds like he's more interested in changing
the first thing than the second one
Bruce and JD seemed to like degree -> workers.
JD also suggested another option that nobody else endorsed.
Alvaro suggested another option that nobody else endorsed.

Does anyone else want to vote?  Does anyone who previously cast a vote
wish to change it or clarify their position?  I think I am reading
that degree -> workers will please most people (just not me).

-- 
Robert Haas
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