[Tom Lane <tgl@sss.pgh.pa.us>]

Robert Haas <robertmhaas@gmail.com> writes:
> On Wed, Aug 16, 2017 at 11:56 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> I can get on board with that statement.  Can you draft a better wording?

> Here is an attempt.  Feel free to edit.

I think s/plan/query/ in the last bit would be better.  Perhaps

+	 * However, if force_parallel_mode = on or force_parallel_mode = regress,
+	 * then we impose parallel mode whenever it's safe to do so, even if the
+	 * final plan doesn't use parallelism.  It's not safe to do so if the query
+	 * contains anything parallel-unsafe; parallelModeOK will be false in that
+	 * case.  Otherwise, everything in the query is either parallel-safe or
+	 * parallel-restricted, and in either case it should be OK to impose
+	 * parallel-mode restrictions.  If that ends up breaking something, then
+	 * either some function the user included in the query is incorrectly
+	 * labelled as parallel-safe or parallel-restricted when in reality it's
+	 * parallel-unsafe, or else the query planner itself has a bug.
 	 */

			regards, tom lane


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