(a) How to calculate the total number of cells of a relation (a cell refers to the intersection of a row and a column of the relation) if you know the cardinality and degree of the relation? (b) When are you formulating the domain of the attributes of a relation, what are the main things that you need to specify in the domain description? (c) What is the key difference between the inner join and outer join? (d) Is SQL a procedural or non-procedural (declarative) language? What are major advantages of SQL being that type of language when compared with the other type of language