Deck 7: Advanced SQL

Question 1

The most commonly used form of join operation is the:

A) outer join.
B) union join.
C) equi-join.
D) natural join.

Answer 1

D

Question 2

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.

Answer 2

B

Question 3

An interactive command that can be used to dynamically control a user session for appropriate integrity measures is:

A) rollback.
B) rollforward.
C) set autocommit.
D) expunge.

Answer 3

C

Question 4

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.

Question 5

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.

Question 6

User-defined transactions can improve system performance because:

A) transactions are processed as sets, reducing system overhead.
B) transactions are mapped to SQL statements.
C) speed is improved due to query optimization.
D) all of the above.

Question 7

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 keyword in a statement.
D) using a subquery.

Question 8

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) uni-lateral join.
C) natural join.
D) both A and C.

Question 9

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) all of the above.

Question 10

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) all of the above.

Question 11

________ 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

Question 12

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, 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.

Question 13

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) none of the above.

Question 14

Explicit commands to manage transactions are needed when:

A) a transaction consists of just one SQL command.
B) multiple SQL commands must be run as part of a transaction.
C) autocommit is set to off.
D) none of the above.

Question 15

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

Question 16

A type of join implemented in SQL-1999 and by extension SQL-2003 that returns all of the data from each table that is joined is called a(n):

A) outer join.
B) inner join.
C) union join.
D) intersect join.

Question 17

A type of join where a table is joined to itself is called a(n)________.

A) unary join
B) self join
C) unnatural join
D) pinned join

Question 18

A ________ is a temporary table used in the FROM clause of an SQL query.

A) correlated subquery
B) derived table
C) view table
D) none of the above

Question 19

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 on the data that you need

Question 20

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.

Question 21

A new set of analytical functions added in SQL:200n are referred to as:

A) OLAF Functions.
B) MOLAP Functions.
C) Average Functions.
D) OLAP Functions.

Question 22

Extensions defined in SQL-99 that include the capability to create and drop modules of code stored in the database schema across user sessions are called:

A) stored procedures.
B) Persistent Stored Modules.
C) flow control modules.
D) none of the above.

Question 23

________ differs from array because it can contain duplicates.

A) BIGINT
B) XML
C) MULTISET
D) TABLE

Question 24

All of the following are new data types added in SQL:200n EXCEPT:

A) BIGINT
B) BIT
C) MULTISET
D) XML

Question 25

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

Question 26

In order to embed SQL inside of another language,the ________ statement must be placed before the SQL in the host language.

A) GET SQL
B) EXEC SQL
C) RUN SQL
D) SQL SQL

Question 27

The joining condition of an equi-join is based upon an equality.

Question 28

Dynamic SQL:

A) is used to generate appropriate SQL code on the fly, as an application is processing.
B) is quite volatile.
C) is not used widely on the Internet.
D) creates a less flexible application.

Question 29

A procedure is:

A) stored within the database.
B) given a unique name.
C) called by name.
D) all of the above.

Question 30

An equi-join is a join in which one of the duplicate columns is eliminated in the result table.

Question 31

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.

Question 32

What results would the following SQL statement produce?
Select owner,table_name
From dba_tables
Where table_name = 'CUSTOMER';

A) A listing of all customers in the customer table
B) A listing of the owner of the customer table
C) A listing of the owner of the customer table as well as customers
D) An error message

Question 33

SQL-invoked routines can be:

A) procedures.
B) functions.
C) all of the above.
D) none of the above.

Question 34

User-defined data types:

A) can be a subclass of a standard type.
B) can behave as an object.
C) can have defined functions and methods.
D) can have all of the above.

Question 35

RANK and DENSE-RANK are examples of:

A) Ceilings.
B) Door Functions.
C) Window Functions.
D) Moving Functions.

Question 36

While triggers run automatically,________ do not and have to be called.

A) trapdoors
B) routines
C) selects
D) updates

Question 37

All of the following are part of the coding structure for triggers EXCEPT:

A) event.
B) condition.
C) selection.
D) action.

Question 38

Embedded SQL consists of:

A) hard-coded SQL statements included in a program written in another language.
B) SQL encapsulated inside of other SQL statements.
C) SQL written into a front-end application.
D) SQL translated to a lower-level language.

Question 39

All of the following are advantages of SQL-invoked routines EXCEPT:

A) flexibility.
B) efficiency.
C) sharability.
D) security.

Question 40

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) none of the above.

Question 41

There is a special operation in SQL to join a table to itself.

Question 42

One major disadvantage of the outer join is that information is easily lost.

Question 43

IF-THEN-ELSE logical processing cannot be accomplished within an SQL statement.

Question 44

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.

Question 45

A correlated subquery is executed once for each iteration through the outer loop.

Question 46

It is better not to have a result set identified before writing group by and having clauses for a query.

Question 47

An SQL query that implements an outer join will return rows that do not have matching values in common columns.

Question 48

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');

Question 49

Figuring out what attributes you want in your query before you write the query will help with query writing.

Question 50

Correlated subqueries are less efficient than queries that do not use nesting.

Question 51

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.

Question 52

Subqueries can only be used in the WHERE clause.

Question 53

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.

Question 54

EXISTS takes a value of false if the subquery returns an intermediate result set.

Question 55

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);

Question 56

The following queries produce the same results.
select 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');

Question 57

A subquery in which processing the inner query depends on data from the outer query is called a codependent query.

Question 58

The UNION clause is used to combine the output from multiple queries into a single result table.

Question 59

Joining tables or using a subquery may produce the same result.

Question 60

The natural join is very rarely used.

Question 61

MULTISET is similar to the table datatype.

Question 62

RDBMSs store database definition information in system-created tables which can be considered a data dictionary.

Question 63

Triggers can be used to ensure referential integrity,enforce business rules,create audit trails,replicate tables,but cannot call other triggers.

Question 64

A function has only input parameters but can return multiple values.

Question 65

A join in which the joining condition is based on equality between values in the common column is called a(n)________.

Question 66

The advantages of SQL-invoked routines are flexibility,efficiency,shareability and applicability.

Question 67

A routine is a named set of SQL statements that are considered when a data modification occurs.

Question 68

Persistent stored modules are extensions defined in SQL:1999 that include the capability to add and drop modules of code.

Question 69

Combining a table with itself results in a faster query.

Question 70

Constraints are a special case of triggers.

Question 71

SQL statements can be included in another language,such as C or Java.

Question 72

A transaction is the complete set of closely related update commands that must all be done,or none of them done,for the database to remain valid.

Question 73

SQL:200n allows one to calculate linear regressions,moving averages and correlations without moving the data outside of the database.

Question 74

The outer join syntax does not apply easily to a join condition of more than ________ tables.

Question 75

A ________ 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.

Question 76

DBA_USERS contains comments on all tables in an Oracle database.

Question 77

Triggers have three parts: the event,the condition,and the action.

Question 78

Using an ________ produces this information: rows that do not have matching values in common columns are also included in the result table.

Question 79

Transaction integrity commands are not used to identify whole units of database changes that must be completed in full for the database to retain integrity.

Question 80

A procedure is run by calling it by its name.