Re: Fix tuple deformation with virtual generated NOT NULL columns

On Tue, 9 Jun 2026 at 14:20, Chao Li <li(dot)evan(dot)chao(at)gmail(dot)com> wrote:
> > On Jun 8, 2026, at 21:01, Andres Freund <andres(at)anarazel(dot)de> wrote:
> > Seems like a test for some of this would be good too?

> Okay, I tried to add a test matching my repro. With this test in place, I reverted the fix and ran make check; it failed by hitting the Assert David added:
> ```
> TRAP: failed Assert("first_null_attr(tup->t_bits, natts) >= firstNullAttr"), File: "execTuples.c", Line: 1083, PID: 65804

I was on the fence about that test as I felt it was mostly
highlighting that there was a bug once with that particular case, and
didn't feel like it did much to prevent future omissions from
TupleDescFinalize(). I felt the Assert would help highlight future
stuff.

However, I don't object to adding the test if others feel it's
worthwhile, but on looking at the patch, there are a couple of things
that stand out.

1. Nothing has been done for the comment at the top of the file that
says "-- keep these tests aligned with generated_stored.sql". It
looks like there have been quite a few commits already which have
neglected this. Maybe that means we should do away with the comment
rather than try to align the two.
2. I can't quite figure out the pattern in these tests for dropping vs
not dropping the tables at the end of the test. Many tests do DROP
TABLE and a large number of others don't bother. What's meant to be
happening here?

I've added Peter as I think it was his intention to keep these tests
aligned with generated_stored.sql.

David