WGU C170 Data Management Problem
Solving Exam Questions and With Distinction
level Marking scheme updated 2024/2025
inner join - correct answer A join operation in which only rows that meet a given
criterion are selected. The most common type of join
outer join - correct answer 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 - correct answer A join operation that returns the Cartesian product of two
sets or tables
natural join - correct answer 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 - correct answer Name the three types of outer joins
ALL - correct answer This operator can be used to compare something to every
returned row of a subquery
ANY - correct answer This operator can be used to compare something to a list of
values and return any rows that satisfy the criteria
correlated subquery - correct answer A subquery that executes once for each row in
the outer query
UNION - correct answer SQL statement that combines rows from two or more queries
without including duplicate rows, as long as the queries return the same # of attributes
and similar data types
, UNION ALL - correct answer SQL statement similar to UNION but retaining duplicate
rows
INTERSECT - correct answer SQL statement used to combine rows from two queries,
returning only the rows that appear in both sets
EXCEPT (MINUS) - correct answer SQL statement that combines rows from two
queries and returns only the rows that appear in the first set but not in the second
view - correct answer A virtual table based on a SELECT query that is saved as an
object in the database
base table - correct answer The table on which a view is based
batch update routine - correct answer A routine that pools transactions into a single
group to update a master table in a single operation
updatable view - correct answer A view that can update attributes in base tables that
are used in the view
True - correct answer One easy way to determine whether a view can be used to
update a base table is if the primary key columns of the base table you want to update
still have unique values in the view, then the base table is updatable
SQL performance tuning - correct answer Activities to help generate a SQL query that
returns the correct answer in the least amount of time, using the minimum amount of
resources at the server end
DBMS performance tuning - correct answer Activities to ensure that clients' requests
are addressed as quickly as possible while making optimum use of existing resources
Solving Exam Questions and With Distinction
level Marking scheme updated 2024/2025
inner join - correct answer A join operation in which only rows that meet a given
criterion are selected. The most common type of join
outer join - correct answer 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 - correct answer A join operation that returns the Cartesian product of two
sets or tables
natural join - correct answer 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 - correct answer Name the three types of outer joins
ALL - correct answer This operator can be used to compare something to every
returned row of a subquery
ANY - correct answer This operator can be used to compare something to a list of
values and return any rows that satisfy the criteria
correlated subquery - correct answer A subquery that executes once for each row in
the outer query
UNION - correct answer SQL statement that combines rows from two or more queries
without including duplicate rows, as long as the queries return the same # of attributes
and similar data types
, UNION ALL - correct answer SQL statement similar to UNION but retaining duplicate
rows
INTERSECT - correct answer SQL statement used to combine rows from two queries,
returning only the rows that appear in both sets
EXCEPT (MINUS) - correct answer SQL statement that combines rows from two
queries and returns only the rows that appear in the first set but not in the second
view - correct answer A virtual table based on a SELECT query that is saved as an
object in the database
base table - correct answer The table on which a view is based
batch update routine - correct answer A routine that pools transactions into a single
group to update a master table in a single operation
updatable view - correct answer A view that can update attributes in base tables that
are used in the view
True - correct answer One easy way to determine whether a view can be used to
update a base table is if the primary key columns of the base table you want to update
still have unique values in the view, then the base table is updatable
SQL performance tuning - correct answer Activities to help generate a SQL query that
returns the correct answer in the least amount of time, using the minimum amount of
resources at the server end
DBMS performance tuning - correct answer Activities to ensure that clients' requests
are addressed as quickly as possible while making optimum use of existing resources
