sql

(1) Consider a relational schema R(A, B, C, D, E) and the following set of functional dependencies valid in the schema List all minimal keys valid in the schema. List all derivations of function dependencies that lead to the identification of minimal keys. Note, that a schema can have more than one minimal key. (2) Consider a relational schema R(A, B, C, D, E) and the following set of functional dependencies valid in the schema A-B, B-CD, C-E, E-AC) List all minimal keys valid in the schema. List all derivations of function dependencies that lead to the identification of minimal keys. Note, that a schema can have more than one minimal key. (3) Consider a relational schema R(A, B, C, D, E) and the following set of functional dependencies valid in the schema, (A -> B, DB -C) List all minimal keys valid in the schema. List all derivations of function dependencies that lead to the identification of minimal keys. Note, that a schema can have more than one minimal kev