WGU C170 - Data Management - Applications Premium
Questions and Verified Answers Pack (A+, verified)
• superkey -✓✓An attribute or attributes that uniquely identify each entity in a table. Any
composite key with this is also this.
• candidate key -✓✓A minimal superkey; that is, a key that does not contain a subset of
attributes that is itself a superkey
• entity integrity -✓✓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 -✓✓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 -✓✓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 -✓✓A detailed system data dictionary that describes all objects in a
database
• homonym -✓✓The use of the same name to label different attributes, much like
similar-sounding words with different meanings
• synonym -✓✓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 -✓✓Any candidate key must have these two constraints enforced
• cardinality -✓✓Term for how many instances of one object are related to instances of
another object (maximum)
• modality -✓✓Term for whether an instance of a specific entity is optional or mandatory
in a relationship (minimum)
• connectivity -✓✓Term for the classification of the relationship between entities.
Classifications include 1:1, 1:M, and M:N
• CREATE SCHEMA AUTHORIZATION -✓✓SQL command to create a database
schema
, • DEFAULT -✓✓SQL option to define a default value for a column (when no value is
given)
• CHECK -✓✓SQL command to validate data in an attribute, used during table column
creation
• CREATE TABLE AS -✓✓SQL command to create a new table based on a query in the
user's database schema
• HAVING -✓✓SQL option that restricts a selection of grouped rows based on a
condition
• EXISTS -✓✓SQL option that checks whether a subquery returns any rows
• DECIMAL -✓✓SQL data type like the NUMBER specification, but the storage length is
a minimum specification
• True -✓✓True or false: if an INSERT or SELECT command is embedded inside a
program for later use, the attribute list should always be used, as the table may change
over time
• inner join -✓✓A join operation in which only rows that meet a given criterion are
selected. The most common type of join
• outer join -✓✓A join operation that produces a table in which all unmatched pairs are
retained; unmatched values in the related table are left null
• cross join -✓✓A join operation that returns the Cartesian product of two sets or tables
• natural join -✓✓Join type that returns only the rows with matching values in the
matching columns; the matching columns must have the same names and similar data
types
• left, right, full -✓✓Name the three types of outer joins
• ALL -✓✓This operator can be used to compare something to every returned row of a
subquery
• ANY -✓✓This operator can be used to compare something to a list of values and
return any rows that satisfy the criteria
• correlated subquery -✓✓A subquery that executes once for each row in the outer
query
Questions and Verified Answers Pack (A+, verified)
• superkey -✓✓An attribute or attributes that uniquely identify each entity in a table. Any
composite key with this is also this.
• candidate key -✓✓A minimal superkey; that is, a key that does not contain a subset of
attributes that is itself a superkey
• entity integrity -✓✓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 -✓✓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 -✓✓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 -✓✓A detailed system data dictionary that describes all objects in a
database
• homonym -✓✓The use of the same name to label different attributes, much like
similar-sounding words with different meanings
• synonym -✓✓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 -✓✓Any candidate key must have these two constraints enforced
• cardinality -✓✓Term for how many instances of one object are related to instances of
another object (maximum)
• modality -✓✓Term for whether an instance of a specific entity is optional or mandatory
in a relationship (minimum)
• connectivity -✓✓Term for the classification of the relationship between entities.
Classifications include 1:1, 1:M, and M:N
• CREATE SCHEMA AUTHORIZATION -✓✓SQL command to create a database
schema
, • DEFAULT -✓✓SQL option to define a default value for a column (when no value is
given)
• CHECK -✓✓SQL command to validate data in an attribute, used during table column
creation
• CREATE TABLE AS -✓✓SQL command to create a new table based on a query in the
user's database schema
• HAVING -✓✓SQL option that restricts a selection of grouped rows based on a
condition
• EXISTS -✓✓SQL option that checks whether a subquery returns any rows
• DECIMAL -✓✓SQL data type like the NUMBER specification, but the storage length is
a minimum specification
• True -✓✓True or false: if an INSERT or SELECT command is embedded inside a
program for later use, the attribute list should always be used, as the table may change
over time
• inner join -✓✓A join operation in which only rows that meet a given criterion are
selected. The most common type of join
• outer join -✓✓A join operation that produces a table in which all unmatched pairs are
retained; unmatched values in the related table are left null
• cross join -✓✓A join operation that returns the Cartesian product of two sets or tables
• natural join -✓✓Join type that returns only the rows with matching values in the
matching columns; the matching columns must have the same names and similar data
types
• left, right, full -✓✓Name the three types of outer joins
• ALL -✓✓This operator can be used to compare something to every returned row of a
subquery
• ANY -✓✓This operator can be used to compare something to a list of values and
return any rows that satisfy the criteria
• correlated subquery -✓✓A subquery that executes once for each row in the outer
query
