WGU C170 ACTUAL TEST PAPER
COMPLETE QUESTIONS AND ANSWERS
FULL SOLUTION
●● An attribute or attributes that uniquely identify each entity in a table.
Any composite key with this is also this.
Answer: superkey
●● A minimal superkey; that is, a key that does not contain a subset of
attributes that is itself a superkey
Answer: candidate key
●● 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
Answer: entity integrity
●● A condition by which a dependent table's foreign key must have
either a null entry or a matching entry in the related table
Answer: referential integrity
●● A DBMS component that stores metadata. It contains the data
definition & their characteristics and relationships; may also include data
external to the DBMS
, Answer: data dictionary
●● A detailed system data dictionary that describes all objects in a
database
Answer: system catalog
●● The use of the same name to label different attributes, much like
similar-sounding words with different meanings
Answer: homonym
●● The use of different names to identify the same object, such as an
entity, an attribute, or a relationship. These should generally be avoided.
Answer: synonym
●● Any candidate key must have these two constraints enforced
Answer: not null and unique
●● Term for how many instances of one object are related to instances of
another object (maximum)
Answer: cardinality
●● Term for whether an instance of a specific entity is optional or
mandatory in a relationship (minimum)
COMPLETE QUESTIONS AND ANSWERS
FULL SOLUTION
●● An attribute or attributes that uniquely identify each entity in a table.
Any composite key with this is also this.
Answer: superkey
●● A minimal superkey; that is, a key that does not contain a subset of
attributes that is itself a superkey
Answer: candidate key
●● 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
Answer: entity integrity
●● A condition by which a dependent table's foreign key must have
either a null entry or a matching entry in the related table
Answer: referential integrity
●● A DBMS component that stores metadata. It contains the data
definition & their characteristics and relationships; may also include data
external to the DBMS
, Answer: data dictionary
●● A detailed system data dictionary that describes all objects in a
database
Answer: system catalog
●● The use of the same name to label different attributes, much like
similar-sounding words with different meanings
Answer: homonym
●● The use of different names to identify the same object, such as an
entity, an attribute, or a relationship. These should generally be avoided.
Answer: synonym
●● Any candidate key must have these two constraints enforced
Answer: not null and unique
●● Term for how many instances of one object are related to instances of
another object (maximum)
Answer: cardinality
●● Term for whether an instance of a specific entity is optional or
mandatory in a relationship (minimum)
