DATA ANALYTICS UTT - CHAPTER 6
The UNION clause is used to: A) combine the output from multiple queries into a single result table. B) join two tables together to form one table. C) find all rows that do not match in two tables. D) find all rows that are in one table, but not the other.
A) combine the output from multiple queries into a single result table.
________ takes a value of TRUE if a subquery returns an intermediate results table which contains one or more rows. A) IN B) HAVING C) EXISTS D) EXTENTS
C) EXISTS
A procedure is: A) stored outside the database. B) given a reserved SQL name. C) called by name. D) unable to be modified.
C) called by name.
User-defined data types: A) are not allowed in any DBMS. B) are only allowed in Oracle. C) can have defined functions and methods. D) can be used once in a system.
C) can have defined functions and methods.
A join in which rows that do not have matching values in common columns are still included in the result table is called a(n): A) natural join. B) equi-join. C) outer join. D) union join.
C) outer join.
All of the following are part of the coding structure for triggers EXCEPT: A) event. B) condition. C) selection. D) action.
C) selection.
SQL provides the ________ technique, which involves placing an inner query within the WHERE or HAVING clause of an outer query. A) grouping B) joining C) subquery D) union
C) subquery
The following code would include: SELECT Customer_T.CustomerID,CustomerName, OrderID FROM Customer_T RIGHT OUTER JOIN Order_T ON Customer_T.CustomerID = Order_T.CustomerID; A) all rows of the Order_T Table regardless of matches with the Customer_T Table. B) all rows of the Customer_T Table regardless of matches with the Order_T Table. C) only rows that match both Customer_T and Order_T Tables. D) only rows that don't match both Customer_T and Order_T Tables.
A) all rows of the Order_T Table regardless of matches with the Customer_T Table.
The MERGE command: A) allows one to combine the INSERT and UPDATE operations. B) allows one to combine the INSERT and DELETE operations. C) joins 2 tables together. D) is always a single table operation.
A) allows one to combine the INSERT and UPDATE operations.
In SQL, a(n) ________ subquery is a type of subquery in which processing the inner query depends on data from the outer query. A) correlated B) paired C) natural D) inner
A) correlated
The following code is an example of a(n): SELECT Customer_T.CustomerID, Order_T.CustomerID, CustomerName, OrderID FROM Customer_T, Order_T WHERE Customer_T.CustomerID = Order_T. CustomerID; A) equi-join. B) subquery. C) Full Outer JOIN. D) Right Outer JOIN.
A) equi-join.
A type of join between three tables is called a(n): A) ternary join. B) self-join. C) unnatural join. D) pinned join.
A) ternary join.
The outer join syntax does not apply easily to a join condition of more than ________ tables. A) two B) three C) four D) five
A) two
What would the following view contain for values? Create view CustomerOrders as Select CustID, Count(*) as TotOrders, Sum(ordertotal) as Value From customer inner join sale on customer.customer_id = sale.customer_id; A) A listing of all customers in the customer table B) A listing of the customer ID as well as the total number of orders and the total amount spent by the customer C) A listing of the customer ID as well as the total orders D) An error message
B) A listing of the customer ID as well as the total number of orders and the total amount spent by the customer
The following code would include: SELECT Customer_T.CustomerID,CustomerName, OrderID FROM Customer_T LEFT OUTER JOIN Order_T ON Customer_T.CustomerID = Order_T.CustomerID; A) all rows of the Order_T Table regardless of matches with the Customer_T Table. B) all rows of the Customer_T Table regardless of matches with the Order_T Table. C) only rows that match both Customer_T and Order_T Tables. D) only rows that don't match both Customer_T and Order_T Tables.
B) all rows of the Customer_T Table regardless of matches with the Order_T Table.
The following statement is an example of: CREATE TABLE Customer_t ( CustNmbr number(11,0), CreditLimit number(6,2), CustStart date, CustEnd date, PERIOD for Custperiod(CustStart,CustEnd)); A) a materialized view. B) an application time period table. C) a system-versioned table. D) a dynamic view.
B) an application time period table.
In order for two queries to be UNION-compatible, they must: A) both have the same number of lines in their SQL statements. B) both output compatible data types for each column and return the same number of rows. C) both return at least one row. D) both return exactly one row.
B) both output compatible data types for each column and return the same number of rows.
A join operation: A) brings together data from two different fields. B) causes two tables with a common domain to be combined into a single table or view. C) causes two disparate tables to be combined into a single table or view. D) is used to combine indexing operations.
B) causes two tables with a common domain to be combined into a single table or view.
A ________ is a temporary table used in the FROM clause of an SQL query. A) correlated subquery B) derived table C) view table D) trigger
B) derived table
SQL-invoked routines can be: A) part of a DDL statement. B) functions or procedures. C) part of a DCL statement. D) contained within a CREATE statement.
B) functions or procedures.
One major advantage of the outer join is that: A) information is easily accessible. B) information is not lost. C) the query is easier to write. D) information's data type changes.
B) information is not lost.
A join that is based upon equality between values in two common columns with the same name and where one duplicate column has been removed is called a(n): A) equi-join. B) natural join. C) multivariate join. D) inner join.
B) natural join.
While triggers run automatically, ________ do not and have to be called. A) trapdoors B) routines C) selects D) updates
B) routines
A type of query that is placed within a WHERE or HAVING clause of another query is called a: A) master query. B) subquery. C) superquery. D) multi-query.
B) subquery.
All of the following are guidelines for better query design EXCEPT: A) understand how indexes are used in query processing. B) use a lot of self-joins. C) write simple queries. D) retrieve only the data that you need.
B) use a lot of self-joins.
In which of the following situations would one have to use an outer join in order to obtain the desired results? A) A report is desired that lists all customers who placed an order. B) A report is desired that lists all customers and the total of their orders. C) A report is desired that lists all customers and the total of their orders during the most recent month, and includes customers who did not place an order during the month (their total will be zero). D) There is never a situation that requires only an outer join.
C) A report is desired that lists all customers and the total of their orders during the most recent month, and includes customers who did not place an order during the month (their total will be zero).
A materialized view is/are: A) a virtual table created dynamically on request by a user. B) an in-line query. C) copies or replica of data based on queries. D) always an exact copy of the source table.
C) copies or replica of data based on queries.
The following code would include: SELECT Customer_T.CustomerID, Order_T.CustomerID, CustomerName, OrderID FROM Customer_T, Order_T WHERE Customer_T.CustomerID = Order_T. CustomerID; A) all rows of the Order_T Table regardless of matches with the Customer_T Table. B) all rows of the Customer_T Table regardless of matches with the Order_T Table. C) only rows that match both Customer_T and Order_T Tables. D) only rows that don't match both Customer_T and Order_T Tables.
C) only rows that match both Customer_T and Order_T Tables.
Establishing IF-THEN-ELSE logical processing within an SQL statement can be accomplished by: A) using the if-then-else construct. B) using the immediate if statement. C) using the CASE key word in a statement. D) using a subquery.
C) using the CASE key word in a statement.
If the DBA wishes to describe all tables in the database, which data dictionary view should be accessed in Oracle? A) DBA_TAB_PRIVS B) DBA_TAB_COMMENTS C) DBA_TABLE_LABEL D) DBA_TABLES
D) DBA_TABLES
A new set of analytical functions added in SQL:2008 is referred to as: A) OLAF functions. B) MOLAP functions. C) average functions. D) OLAP functions.
D) OLAP functions.
________ use the result of the inner query to determine the processing of the outer query. A) Correlated subqueries B) Outer subqueries C) Inner subqueries D) Subqueries
D) Subqueries
The ________ operator is used to combine the output from multiple queries into a single result table. A) INTERSECT B) DIVIDE C) COLLATE D) UNION
D) UNION
A join in which the joining condition is based on equality between values in the common columns is called a(n): A) equi-join. B) unilateral join. C) natural join. D) both A and C.
D) both A and C.
When a user creates a virtual table it is called a(n): A) materialized view. B) virtual table. C) inline view. D) dynamic view.
D) dynamic view.
The most commonly used form of join operation is the: A) outer join. B) union join. C) equi-join. D) natural join.
D) natural join.
All of the following are advantages of SQL-invoked routines EXCEPT: A) flexibility. B) efficiency. C) sharability. D) security.
D) security.
T/F: A subquery in which processing the inner query depends on data from the outer query is called a codependent query.
FALSE
T/F: An equi-join is a join in which one of the duplicate columns is eliminated in the result table.
FALSE
T/F: Combining a table with itself results in a faster query.
FALSE
T/F: EXISTS takes a value of false if the subquery returns an intermediate result set.
FALSE
T/F: IF-THEN-ELSE logical processing cannot be accomplished within an SQL statement.
FALSE
T/F: It is better not to have a result set identified before writing GROUP BY and HAVING clauses for a query.
FALSE
T/F: One major disadvantage of the outer join is that information is easily lost.
FALSE
T/F: Specifying the attribute names in the SELECT statement will make it easier to find errors in queries and also correct for problems that may occur in the base system.
FALSE
T/F: Subqueries can only be used in the WHERE clause.
FALSE
T/F: The following code is an example of a Subquery. SELECT Customer_T.CustomerID, Order_T.CustomerID, CustomerName, OrderID FROM Customer_T, Order_T WHERE Customer_T.CustomerID = Order_T. CustomerID;
FALSE
T/F: The following code is an example of a correlated subquery. SELECT CustomerName, CustomerAddress, CustomerCity, CustomerState, CustomerPostalCode FROM Customer_T WHERE Customer_T.CustomerID = (SELECT Order_T.CustomerID FROM Order_T WHERE OrderID = 1008);
FALSE
T/F: The following query will execute without errors. SELECT Customer.Customer_Name, Salesman.Sales_Quota FROM Customer WHERE Customer.Salesman_ID =(SELECT Salesman_ID WHERE Lname = 'SMITH');
FALSE
T/F: Triggers can be used to ensure referential integrity, enforce business rules, create audit trails, and replicate tables, but cannot call other triggers.
FALSE
T/F: User-defined functions can improve system performance because they will be processed as sets rather than individually, thus reducing system overhead.
FALSE
T/F: Using an outer join produces this information: rows that do not have matching values in common columns are not included in the result table.
FALSE
T/F: When a subquery is used in the FROM clause, it is called a denied table.
FALSE
T/F: A base table is the underlying table that is used to create views.
TRUE
T/F: A correlated subquery is executed once for each iteration through the outer loop.
TRUE
T/F: A dynamic query is created by the user.
TRUE
T/F: A join in which the joining condition is based on equality between values in the common column is called an equi-join.
TRUE
T/F: A materialized view is not persistent.
TRUE
T/F: A natural join is the same as an equi-join, except that it is performed over matching columns that have been defined with the same name, and one of the duplicate columns is eliminated.
TRUE
T/F: A procedure is run by calling it by its name.
TRUE
T/F: A trigger is a named set of SQL statements that are considered when a data modification occurs.
TRUE
T/F: An SQL query that implements an outer join will return rows that do not have matching values in common columns.
TRUE
T/F: Constraints are a special case of triggers.
TRUE
T/F: Correlated subqueries are less efficient than queries that do not use nesting.
TRUE
T/F: Establishing IF-THEN-ELSE logical processing within an SQL statement can now be accomplished by using the CASE keyword in a statement.
TRUE
T/F: In order to find out what customers have not placed an order for a particular item, one might use the NOT qualifier along with the IN qualifier.
TRUE
T/F: SQL allows one to calculate linear regressions, moving averages, and correlations without moving the data outside of the database.
TRUE
T/F: The UNION clause is used to combine the output from multiple queries into a single result table.
TRUE
T/F: The advantages of SQL-invoked routines are flexibility, efficiency, sharability, and applicability.
TRUE
T/F: The following queries produce the same results. SELECT DISTINCT Customer_Name, Customer_City FROM Customer, Salesman WHERE Customer.Salesman_ID = Salesman.Salesman_ID and Salesman.Lname = 'SMITH'; SELECT Customer_Name, Customer_City FROM Customer WHERE Customer.Salesman_ID = (SELECT Salesman_ID FROM Salesman WHERE Lname = 'SMITH');
TRUE
T/F: The joining condition of an equi-join is based upon an equality.
TRUE
T/F: Triggers have three parts: the event, the condition, and the action.
TRUE
T/F: When EXISTS or NOT EXISTS is used in a subquery, the select list of the subquery will usually just select all columns as a placeholder because it doesn't matter which columns are returned.
TRUE
The following code is an example of a: SELECT CustomerName, CustomerAddress, CustomerCity, CustomerState, CustomerPostalCode FROM Customer_T WHERE Customer_T.CustomerID = (SELECT Order_T.CustomerID FROM Order_T WHERE OrderID = 1008); A) correlated subquery. B) subquery. C) join. D) FULL OUTER JOIN.
B) subquery.
A named set of SQL statements that are considered when a data modification occurs are called: A) stored procedures. B) treatments. C) triggers. D) trapdoors.
C) triggers.
EXISTS will take a value of ________ if the subquery returns an intermediate results table which contains one or more rows. A) false B) 1 C) true D) undefined
C) true
T/F: MULTISET is similar to the table datatype.
FALSE
T/F: The natural join is very rarely used.
FALSE
T/F: There is a special operation in SQL to join a table to itself.
FALSE
T/F: Figuring out what attributes you want in your query before you write the query will help with query writing.
TRUE
T/F: Joining tables or using a subquery may produce the same result.
TRUE
T/F: The following SQL statement is an example of a correlated subquery. SELECT First_Name, Last_Name, Total_Sales FROM Salesman s1 WHERE Total_Sales > all (SELECT Total_Sales FROM Salesman s2 WHERE s1.Salesman_ID != s2.Salesman_ID);
TRUE
An operation to join a table to itself is called a(n): A) sufficient-join. B) inner join. C) outer join. D) self-join.
D) self-join.
T/F: A function has only input parameters but can return multiple values.
FALSE
T/F: A routine is a named set of SQL statements that are considered when a data modification occurs.
FALSE
The ________ DBA view shows information about all users of the database in Oracle. A) DBA_USERS B) USERS C) DBA_VIEWS D) DBA_INDEXES
A) DBA_USERS
