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4 Cards in this Set
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Which of the following properties must be observed when using normalization to perform a decomposition of a relation into a set of smaller relations? a. There must be no duplicated columns in any of the smaller relations (i.e., given any pair of relations from the set of smaller relations, there is no shared column) b. A constraint in the original relation can be enforced by one or more constraints on each of the smaller relations c. Any column that contains a multi-valued attribute in the original relation must be included as a column containing a multi-valued attribute in at least one of the smaller relations. d. Any tuple in the original relation can be re-constructed from corresponding tuples in the smaller relations |
b. A constraint in the original relation can be enforced by one or more constraints on each of the smaller relations d. Any tuple in the original relation can be re-constructed from corresponding tuples in the smaller relations |
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Suppose we have the following two functional dependencies A,B --> C A --> C The 1st dependency is called |
A partial functional dependency |
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Which of the following statements accurately characterizes normalization a. It is a high-level design technique that use a diagrammatic notation to model entities, relationships, and attributes. b. Third normal form involves transferring attributes with transitive dependencies to their own relations c. A relation is in second normal form when it is in first normal form and every non-primary-key attribute is fully functionally dependent on the primary key d. A relation that contains a multi-valued attribute is in 1st normal form e. It attempts to decompose relations into groupings of logically related attributes based on functional dependencies between attributes f. Normalization attempts to preserve functional dependencies by placing functionally dependent attributes in the same relation g. Normalization and ER diagrams are mutually exclusive methods for designing a database |
b. Third normal form involves transferring attributes with transitive dependencies to their own relations c. A relation is in second normal form when it is in first normal form and every non-primary-key attribute is fully functionally dependent on the primary key e. It attempts to decompose relations into groupings of logically related attributes based on functional dependencies between attributes. f. Normalization attempts to preserve functional dependencies by placing functionally dependent attributes in the same relation |
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The left side of a functional dependency is called |
The determinant |
