On Fri, Apr 10, 2026 at 10:30 AM Tender Wang <[email protected]> wrote: > SATYANARAYANA NARLAPURAM <[email protected]> 于2026年4月10日周五 02:43写道： > > It appears the optimizer incorrectly simplifies old.<col> IS NULL to FALSE > > in RETURNING clauses when the underlying column has a NOT NULL constraint. > > > > The issue is that var_is_nonnullable() in clauses.c doesn't check > > Var.varreturningtype. It sees a NOT NULL column and concludes the Var can > > never be NULL. > > But this assumption is wrong for old.* and new.* references. Because the > > old tuple doesn't exist on INSERT, and the new tuple doesn't exist on DELETE
Nice catch. > Yes, the current var_is_nonnullable() ignores this case. The > attached patch seems ok to me. The patch also LGTM. I also checked if has_notnull_forced_var() has the same issue, but it doesn't: Vars with non-default returning type only appear in the RETURNING clause, so they never show up in WHERE/ON clauses. - Richard
