Proper database design is the single most important factor for the ensuring performance and maintainability of the database. Here is what you need to answer when designing a table: Can I reduce the size of data that each row will have? Here is what you can do: Use unsigned numeric values when the application will not store negative numbers. Like the “quantity ordered” of an item in an ecommerce application is never going to be -$125. Use Variable length values instead of fixed length value i.e. used varchar instead of char. Do not use unnecessarily large field sizes. For most ecommerce application “unsigned smallint” is more than enough to store inventory count. A field described as “unsigned smallint” can store a max value of 65535.

Don’t ignore normalization; its helps prevent unnecessary repetition of data. The part B of this is, don’t overuse normalization. If the table will not grow in size significantly, there is no point in normalization. For example, if the user table has just 20 rows (i.e. 20 employees in a company), all attempts of normalization are wasted. Use Keys. Don’t decide keys by “The customer id has to be indexed in the order table”. If the order table is being searched 90% of the times by “order date”, it makes more sense to index “order date”. Remember, how a table will be used should determine how it is designed. Spending time here will save years of frustration.