Database Systems

Question 2: Express RDS S(Full outer join) using a subset of the following relational algebra operations (Project, Select, Rename, Union, Intersection, Set Difference, Cartesian product, Join (conditional or natura)1). Explain your assumptions, if any. We assume that attributes of S is denoted as ATTR(S), attributes of R is denoted as ATTR(R) and (ATTR(R)-ATTR(S) denotes a set of attributes in R that does not belong to S. We also use the notation Mat,a2,a3,.. an (NULL) to denote a relation M with attributes (a1, a2, a3, ..an) with one tuple whose values are all null. For example Mid,name (NULL) will be