When you design your database, you need to do it right; otherwise, you may see which of the following issues?

If you delete one set of data, you need to delete another set even if you do not want to delete that second set.

You need to keep a set of data that are useless to make your reporting effective.

If you delete one set of data, you need to update all your records.

The same primary key is used in multiple records, which can cause duplication.