SQL Transactions Exercises
For the universal relation R(w,x,y,z), consider the decomposition D consisting of R1(w,y,z) and R2(x,y), and the set F of functional dependencies { y->xz ; yz->w ; x->w }.
Recall that the projection of set of functional dependences G on relation Rx consists of every functional dependency in (G)+ that contains only attributes from Rx.
a. Compute the projection of F on R1.
b. Compute the projection of F on R2.
c. Does the decomposition D preserve the set of dependencies F? Why or why not?