Re: Inadequate parallel-safety check for SubPlans

Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> writes:
> On Wed, Apr 19, 2017 at 1:27 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> I think leaving that sort of thing out is just creating a latent bug
>> that is certain to bite you later. It's true that as long as the args
>> list contains only Vars, it would never be parallel-unsafe --- but
>> primnodes.h is pretty clear that one shouldn't assume that it will
>> stay that way.

> Sure, but the point I was trying to make was whenever subplan has
> args, I think it won't be parallel-safe as those args are used to pass
> params.

Right now, yes, but surely we're going to be trying to relax that sometime
soon. And at that point it would be a latent bug for this function to
not recurse into the args list. Whatever the restrictions are on the
tree as a whole, they'll apply to that subtree too.

regards, tom lane