How to determine candidate keys from record schema and functional dependencies?
If I have a schema say R={A,B,C,D}
and functional depen开发者_如何学Cdencies say {B->C, D->A}
will my set of candidate keys be {B,D}
or {BD}
?
If B were a candidate key, you'd have to be able to derive these functional dependencies from the ones given in the problem.
- {B->A}
- {B->C}
- {B->D}
Can you do that?
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