Home/ Questions/Q 7848367
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-06-02T18:10:33+00:00

I am asking this question because if a table has a key that consists

  • 0

I am asking this question because if a table has a key that consists of all of is attributes then the table would have a trivial functional dependency since the right side is a subset of the left side.
For example I have relation R with attributes A and B. A and B together are the key of the relation R. Thus I have FD A B -> A B which is a trivial dependency and thus this table only has trivial functional dependencies.

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    Well, you pretty much answered your own question, let me try to restate it in a (hopefully) clearer way…

    • All attributes are functionally dependent on the key.
    • If the key “covers” all attributes, then all these dependencies are trivial (by definition).
    • OTOH, if there are attributes outside the key (even within another key), then they are non-trivially dependent on the key (again, by definition).
    • 0