So ... one of the things that's been worrying me about this patch from day one is whether it would create a noticeable performance penalty for existing use-cases. I did a small amount of experimentation about that with the v35 patchset, and it didn't take long at all to find that this:
--- cut --- create or replace function arraytest(n int) returns void as $$ declare a int[]; begin a := array[1, 1]; for i in 3..n loop a[i] := a[i-1] - a[i-2]; end loop; end; $$ language plpgsql stable; \timing on select arraytest(10000000); --- cut --- is about 15% slower with the patch than with HEAD. I'm not sure what an acceptable penalty might be, but 15% is certainly not it. I'm also not quite sure where the cost is going. It looks like 0001+0002 aren't doing much to the executor except introducing one level of subroutine call, which doesn't seem like it'd account for that. I don't think this can be considered RFC until the performance issue is addressed. regards, tom lane