Hi I try to build a right schema for my table.
I have tuples {X_i, Y_j} and I have to answer to two kinds of queries: Y_j getYvalue(X_i) : given a value X_i, return me the corresponding value Y_j X_i getYvalue(Y_j) : given a value Y_j, return me the corresponding value X_i The easiest way would be to define two tables : one with Keys {X_i} and the second with Keys {Y_j} Does it exist a better way? Thanks! Benjamin