On Thu, May 28, 2020 at 1:36 PM amul sul <sulamul@gmail.com> wrote: > On Wed, May 27, 2020 at 12:53 PM Amit Langote <amitlangote09@gmail.com> wrote: >> Actually, if you declare the cursor without FOR SHARE/UPDATE, the case >> would fail even with traditional inheritance: >> >> drop table if exists p cascade; >> create table p (a int); >> create table c (check (a = 2)) inherits (p); >> insert into p values (1); >> insert into c values (2); >> begin; >> declare c cursor for select * from p where a = 1; >> fetch c; >> update p set a = a where current of c; >> ERROR: cursor "c" is not a simply updatable scan of table "c" >> ROLLBACK >> > > I am not sure I understood the point, you'll see the same error with declarative > partitioning as well.
My point is that if a table is not present in the cursor's plan, there is no way for CURRENT OF to access it. Giving an error in that case seems justified.
OTOH, when the CURRENT OF implementation has RowMarks to look at, it avoids the error for traditional inheritance children due their inactive RowMarks being present in the cursor's PlannedStmt. I think that's only by accident though.
