bug: Postgres cannot yet reliably handle null typed columns

[lmores]

What happened?

I am trying to insert into this PostgreSQL table

CREATE TABLE address (
    id bytea NOT NULL,
    another_id bytea NULL,
    full_address varchar NULL,
    recipient varchar NULL,
    street varchar NULL,
    street2 varchar NULL,
    "number" varchar NULL,
    zip_code varchar NULL,
    city varchar NULL,
    subdivision_code varchar NULL,
    country_code varchar NULL,
    CONSTRAINT raw_address_pkey PRIMARY KEY (id)
);

the following instance of a Python dataclass

@dataclass(frozen=True, slots=True)
class Address:
    id: bytes
    another_id: bytes | None
    full_address: str

    recipient: str | None = None
    street: str | None = None
    street2: str | None = None
    number: str | None = None
    zip_code: str | None = None
    city: str | None = None
    subdivision_code: str | None = None
    country_code: str | None = None

record = Address(
    id=b'...some bytes...',
    another_id=None,
    full_address='SOME TEXT',
    recipient='FOO',
    street='BAR STREET',
    street2=None, number='',
    zip_code='ZIP',
    city='AA',
    subdivision_code='US',
    country_code=None
)

con  # DuckDbBackend instance
con.insert('address', [record])

However, I get the following error:

Traceback (most recent call last):
  File "**OMISSIS**/client.py", line 53, in insert_addresses
    self.con.insert('address', [record])  # type: ignore
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "**OMISSIS**/.venv/lib/python3.12/site-packages/ibis/backends/sql/__init__.py", line 405, in insert
    self._run_pre_execute_hooks(obj)
  File "**OMISSIS**/.venv/lib/python3.12/site-packages/ibis/backends/__init__.py", line 1144, in _run_pre_execute_hooks
    self._register_in_memory_tables(expr)
  File "**OMISSIS**/.venv/lib/python3.12/site-packages/ibis/backends/__init__.py", line 1119, in _register_in_memory_tables
    self._register_in_memory_table(memtable)
  File "**OMISSIS**/.venv/lib/python3.12/site-packages/ibis/backends/postgres/__init__.py", line 112, in _register_in_memory_table
    raise exc.IbisTypeError(
ibis.common.exceptions.IbisTypeError: postgres cannot yet reliably handle `null` typed columns; got null typed columns: ['another_id', 'street2', 'country_code']

I am not sure about its meaning, seems that Ibis does not support the insertion of NULL values even in columns of Postgres tables that allow NULL values... is it?

What version of ibis are you using?

9.5.0

What backend(s) are you using, if any?

PostgreSQL 13.5

Relevant log output

No response

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