Is it possible to create an index for a column only for null, or only for non-null?

Question

MySQL

When you create an index for a column, a new table for indexes is created and the database grows. I need to index only values ​​with null data. To search for 'where column = null'. This will make the database a little smaller than if the contents of the value were not null.

Answer 1

it doesn't happen, make two tables then

Answer 2

When you create an index for a column, a new table is created for the indexes

This is not a table.

To search for 'where column = null'.

This condition does not require an index or even data. By definition, an empty sample at the parser stage.
If we are talking about where column is null - this happens in principle, a partial index is called. But mysql still can't do that.