Re: [HACKERS] [PATCH] Generic type subscripting

Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> On Thu, Jan 11, 2018 at 1:15 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> I think you missed the point. The question is whether the existence of a
>> subscripting function means that we need to treat the subscriptable type
>> as physically containing the subscript result type.

> I don't think I missed the point at all -- this is the exact same set
> of issues that arise with respect to functions. Indeed, I gave an
> example of a function that needs to be updated if a column of the
> input type is altered. In the case of functions, we've decided that
> it's not our problem.

Right, but in the case of stored arrays, we've decided that it *is*
our problem (as indeed it must be, because the user has no tools with
which they could fix a representation change for stored data). The
question is to what extent that need would propagate to pseudo array
types.

> In other words, we're vigorously agreeing.

I think we're agreed on what should be in the v1 version of the patch.
I'm not 100% convinced that the problem won't come up eventually.

regards, tom lane