Suppose we have the following simple relation schema for a political contributio

Question

Suppose we have the following simple relation schema for a political contribution database: Write the key of the relation as a functional dependency: Continuing with the schema in the previous problem, is there any redundancy problem with this relation schema: yes no it's not possible to say from the schema alone. Is there a non-trivial functional dependency in the schema, where the "left-hand side" the functional dependency has fewer attributes than the primary key? If your answer is yes. write the functional dependency, Continuing with the same schema, is the schema in first normal form? it would depend on how the attribute domains were defined. Suppose a relational schema has only attributes s and t. and attribute s is the primary key. Is there a functional dependency between the two attributes? Can't tell from the information given there is a functional dependency s rightarrow t and possibly also there is a functional dependency t rightarrow s and possibly also s rightarrow Suppose a relational schema has only attributes s. t. and u, and that the attribute s and form a candidate key for the relation. Then is s, t rightarrow u a functional dependency? Suppose a relational schema has only attributes s and t. Is s rightarrow s a functional dependency? it depends on the data Is the three-table schema we have seen for the campaign contribution data in first normal form? Suppose b is a functional dependency, and b rightarrow d is a functional dependency. Then is also a functional dependency? Suppose we have a table T with the following schema: artist(id. name, genre, label) Then we run this query on the table:

Explanation / Answer

a)

Relation: contribution (candidate_name, candidate_id, amount, date)

Key of the relation is candidate_id.

Key of the relation as functional dependency: candidate_idà candidate_name, amount, date

b)

There is no redundancy problem if we consider candidate_id as primary key.

d)

The relation is in first normal form as there are no repetitive groups.

g) No

i) No. b->c, b->d, b->cd

j. b) No. It gives syntax error.

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