i am trying to upgrade an existing database for online job finding and hiring website, the main goal is to make the table for people more browsble by adding categories, features, better tag system, and subcategories
here is the problem: each category have it's own subcategory and features, for example when a user is seeing people in teaching category, the user might want to find out if they teach privatly(home-school)so i add a bit type colume for that feature, but as you might know, not all categories need a home schooling feature, for example other categories like, computer, engnier, medican and other stuff, that means all of these rows with category other than teaching will all have a useless "NULL" in them that takes a 1 byte that might not sound a lot but at the end i might end up having tons of such useless "NULL"s in each row that wasting space.
i also can't create table for each category since the people table have realtions with other tables like users,comments, images and etc....
what do you suggest i do?
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