How to store characteristics for different product categories?

Question

Database design

Tell me, how to properly store characteristics for different categories of goods in the database, so that later they can be pulled out for a certain category?

Answer 1

A category directory with an artificial primary key and a product directory with a category foreign key.

Answer 2

json - we store everything in the product, if the signs in the category need to be changed in bulk - we go through the script through all of them. json in postgres is slightly faster than EAV
EAV - a
redis classic or even its own binary file - we store signs in the form of binary masks, for very fast filtering (there was an article on Habré)