Should data type of admittime, dischtime columns in admissions table be annotated as "TIMESTAMP(0) NOT NULL"?

[sunrimii]

As title, I tried the two queries:

SELECT COUNT(*) FROM mimic_core.admissions WHERE dischtime IS NULL

SELECT COUNT(*) FROM mimic_core.admissions WHERE admittime IS NULL

and I got zero of both.

[sunrimii]

Here's another similar issue, there are many null in hadm_id column in edstays table, I think "not null" should be removed.

[sunrimii]

Oops, I just found I post it on wrong place, it should be posted on mimic-iv-website.