在线订购系统的数据库设计

While designing an online shop database I had a problem with one part, could please someone give me an advise whether it is designed ok? The idea is that there are products which can be assigned to categories. Each category has a set of parameters for an easier search of products by customers. For example, a category "CPU" will have parameters "cpu family", "cpu speed" and category "HDD" will have "form factor" and "spindle speed". These parameter names are stored in the table tbCatParam and values of parameters for each product are in the table tbProdCatParam. While designing an online shop database I had a