FDS

Consider a relation R(A,B,C,D,E) with the following dependencies:
{AB-> C, CD -> E, DE -> B}
List all candidate keys.
ANS=
To find the candidate keys for the given relation R(A, B, C, D, E) with the functional dependencies {AB->C, CD->E, DE->B},

1. Check {A}:

   • {A+} = {A}

2. Check {B}:

   • {B+} = {B}

3. Check {C}:

   • {C+} = {C}

4. Check {D}:

   • {D+} = {D}

5. Check {E}:

   • {E+} = {E}

6. Check {AB}:

   • {AB+} = {ABCE}

7. Check {AC}:

   • {AC+} = {AC}

8. Check {AD}:

   • {AD+} = {AD}

9. Check {AE}:

   • {AE+} = {AE}

10. Check {BC}:

    • {BC+} = {BC}

11. Check {BD}:

    • {BD+} = {BD}

12. Check {BE}:

    • {BE+} = {BE}

13. Check {CD}:

    • {CD+} = {CDEB}

14. Check {CE}:

    • {CE+} = {CE}

15. Check {DE}:

    • {DE+} = {DEB}
    • {AB} and {CD} are the candidate keys for the given relation R(A, B, C, D, E) with the provided functional dependencies.