WGU C170 Data Management – Applications Exam Questions with Correct Answers

Domain Correct Answer In data modeling, the construct used to organize and describe an attribute's set of possible values Superkey Correct Answer An attribute or attributes that uniquely identify each entity in a table. Any composite key with this is also this. Candidate key Correct Answer A minimal superkey; that is, a key that does not contain a subset of attributes that is itself a superkey Entity integrity Correct Answer The property of a relational table that guarantees each entity has a unique value in a primary key and that the key has no null values Referential integrity Correct Answer A condition by which a dependent table's foreign key must have either a null entry or a matching entry in the related table Data dictionary Correct Answer A DBMS component that stores metadata. It contains the data definition & their characteristics and relationships; may also include data external to the DBMS System catalog Correct Answer A detailed system data dictionary that describes all objects in a database Homonym Correct Answer The use of the same name to label different attributes, much like similar-sounding words with different meanings Synonym Correct Answer The use of different names to identify the same object, such as an entity, an attribute, or a relationship. These should generally be avoided. Not null and unique Correct Answer Any candidate key must have these two constraints enforced Cardinality Correct Answer Term for how many instances of one object are related to instances of another object (maximum) Modality Correct Answer Term for whether an instance of a specific entity is optional or mandatory in a relationship (minimum) Connectivity Correct Answer Term for the classification of the relationship between entities. Classifications include 1:1, 1:M, and M:N