I have two columns with type DATE: start_date and end_date, I would like to merge them into one sorted column.

I can declare: TYPE merge_date_column IS TABLE OF DATE
INDEX BY BINARY_INTEGER

And then insert the start_date and end_date columns values into it, but the problem is that I don’t know how to sort this type.

Is there any way to sort this type, or is it any better way to do it?