A NULL value in databases is a system value that takes up one byte of storage and indicates that a value is not present as opposed to a space or zero or any other default value.

Does a NULL value Contain space?

It is very important to understand that a NULL value is different than a zero value or a field that contains spaces, spaces are considered as values because they are strings (and sql can't tell what the value of a string means to the user per se), but a NULL signifies a missing value, and hence has no value associated ...

Does a NULL column take up space?

When you store a NULL value in a fixed-length column such as a column with INT data type, the NULL value will consume the whole column length. ... Using Sparse Columns, NULL value will not consume any space regardless of using fixed-length or variable-length columns.