Oracle 21c

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CREATE TABLE table_name (
  id          NUMBER GENERATED ALWAYS AS IDENTITY,
  column_name NUMBER
);
INSERT INTO table_name (column_name) VALUES (NULL);
1 rows affected

INSERT INTO table_name (column_name) VALUES (NULL);
1 rows affected

SELECT id, MAX(column_name) OVER () FROM table_name;


ID
MAX(COLUMN_NAME)OVER()


1
null

2
null


INSERT INTO table_name (column_name) VALUES (42);
1 rows affected

SELECT id, MAX(column_name) OVER () FROM table_name;


ID
MAX(COLUMN_NAME)OVER()


1
42

2
42

3
42

ID	MAX(COLUMN_NAME)OVER()
1	null
2	null