WGU C170 COMPREHENSIVE EXAM STUDY
GUIDE COMPLETE QUESTIONS AND
SOLUTIONS
●● associative entity
Answer: See composite entity.
●● bridge entity
Answer: See composite entity.
●● candidate key
Answer: A minimal superkey; that is, a key that does not contain a
subset of attributes that is itself a superkey. See key.
●● closure
Answer: A property of relational operators that permits the use of
relational algebra operators on existing tables (relations) to produce new
relations.
●● composite entity
Answer: An entity designed to transform an M:N relationship into two
1:M relationships. The composite entity's primary key comprises at least
,the primary keys of the entities that it connects. Also known as a bridge
entity or associative entity. See also linking table.
●● composite key
Answer: A multiple-attribute key.
●● dependent
Answer: An attribute whose value is determined by another attribute.
●● determination
Answer: The role of a key. In the context of a database table, the
statement "A determines B" indicates that knowing the value of attribute
A means that the value of attribute B can be looked up.
●● DIFFERENCE
Answer: In relational algebra, an operator used to yield all rows from
one table that are not found in another union-compatible table.
●● DIVIDE
Answer: In relational algebra, an operator that answers queries about one
set of data being associated with all values of data in another set of data.
●● domain
, Answer: In data modeling, the construct used to organize and describe
an attribute's set of possible values.
●● entity integrity
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.
●● equijoin
Answer: A join operator that links tables based on an equality condition
that compares specified columns of the tables.
●● flags
Answer: Special codes implemented by designers to trigger a required
response, alert end users to specified conditions, or encode values. Flags
may be used to prevent nulls by bringing attention to the absence of a
value in a table.
●● foreign key (FK)
Answer: An attribute or attributes in one table whose values must match
the primary key in another table or whose values must be null. See key.
●● full functional dependence
Answer: A condition in which an attribute is functionally dependent on a
composite key but not on any subset of the key.
GUIDE COMPLETE QUESTIONS AND
SOLUTIONS
●● associative entity
Answer: See composite entity.
●● bridge entity
Answer: See composite entity.
●● candidate key
Answer: A minimal superkey; that is, a key that does not contain a
subset of attributes that is itself a superkey. See key.
●● closure
Answer: A property of relational operators that permits the use of
relational algebra operators on existing tables (relations) to produce new
relations.
●● composite entity
Answer: An entity designed to transform an M:N relationship into two
1:M relationships. The composite entity's primary key comprises at least
,the primary keys of the entities that it connects. Also known as a bridge
entity or associative entity. See also linking table.
●● composite key
Answer: A multiple-attribute key.
●● dependent
Answer: An attribute whose value is determined by another attribute.
●● determination
Answer: The role of a key. In the context of a database table, the
statement "A determines B" indicates that knowing the value of attribute
A means that the value of attribute B can be looked up.
●● DIFFERENCE
Answer: In relational algebra, an operator used to yield all rows from
one table that are not found in another union-compatible table.
●● DIVIDE
Answer: In relational algebra, an operator that answers queries about one
set of data being associated with all values of data in another set of data.
●● domain
, Answer: In data modeling, the construct used to organize and describe
an attribute's set of possible values.
●● entity integrity
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.
●● equijoin
Answer: A join operator that links tables based on an equality condition
that compares specified columns of the tables.
●● flags
Answer: Special codes implemented by designers to trigger a required
response, alert end users to specified conditions, or encode values. Flags
may be used to prevent nulls by bringing attention to the absence of a
value in a table.
●● foreign key (FK)
Answer: An attribute or attributes in one table whose values must match
the primary key in another table or whose values must be null. See key.
●● full functional dependence
Answer: A condition in which an attribute is functionally dependent on a
composite key but not on any subset of the key.
