Re: BUG #15324: Non-deterministic behaviour from parallelised sub-query

Amit Kapila <amit.kapila16@gmail.com> writes:
> On Mon, Aug 20, 2018 at 4:20 PM, Amit Kapila <amit.kapila16@gmail.com> wrote:
>> On Thu, Aug 16, 2018 at 9:25 AM, Amit Kapila <amit.kapila16@gmail.com> wrote:
> On Wed, Aug 15, 2018 at 4:40 PM, Stephen Frost <sfrost@snowman.net> wrote:
>>> (b) Consider the presence of any window function calculation as
>>> parallel-restricted operation.

>> For this, we need to mark all the window functions like row_number,
>> rank, dense_rank, etc as parallel-restricted.   Additionally, we also
>> need to detect the presence of aggregate functions that act as window
>> functions (when an OVER clause follows the call).   Attached patch
>> treat_window_func_calc_parallel_restricted_v1 implements the fix.

> As this patch changes the catalog contents, we need to bump catalog
> version number.  However, I have left it for later once we get a
> review and or testing of the patch.

Sounds to me like you're using the wrong approach.  I would just consider
any Agg or WindowFunc node as parallel-restricted regardless of the
function it references.

            regards, tom lane