Re: print_path is missing GatherMerge and CustomScan support

On Thu, Jul 19, 2018 at 10:41:10AM +0530, Ashutosh Bapat wrote:
> I had extensive testcases in my original patch-set to exercise that
> code but 1. that testset was too extensive; even today
> partition_join.sql is a separate testcase and it's quite large. 2.
> that function returns NULL rather than throwing an error, if it can
> not produce a parameterized path. So, unless we check whether each of
> those paths get created no test is useful and that can only be done
> through an EXPLAIN OUTPUT which means that the testcase becomes
> fragile. I fine if we want to add more tests just to cover the code if
> those are not as fragile and do not blow up partition_join too much.

Did those really check the reparameterization of a MergeAppendPath for a
child of the parent? I'd be surprised if this one was stressed as there
was no match in the list.
--
Michael