Amit Langote <amitlangote09@gmail.com> writes:
> On Tue, Sep 15, 2020 at 9:09 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> I wrote a quick patch for this part. It seems pretty safe and probably
>> could be back-patched without fear.
> The patch's theory that if the parent column has NOT NULL set then it
> must be set in child tables too does not actually hold for plain
> inheritance cases, because as shown above, NOT NULL can be dropped in
> children independently of the parent.
Ah, right. That seems like a bug but we have not attempted to fix it.
But we could restrict the optimization to partitioned tables, where
the assumption does hold, no?
regards, tom lane