Infoman Midterms

Question 1

Each table in a relational database must have a primary key. [T/F]

Answer 1

True

Question 2

A data dictionary contains metadata—data about data.[T/F]

Answer 2

True? (Google answer) (canvas answer =False)

Question 3

A proper understanding of the concept and use of keys in a relational database model is very important. [T/F]

Answer 3

True

Question 4

You can think of a table as a persistent representation of a logical relation.[T/F]

Answer 4

True

Question 5

There is never a good reason to use null values in a database.[T/F]

Answer 5

False? (Google answer) (canvas answer =True)

Question 6

Numeric data are data on which you can perform meaningful arithmetic procedures.[T/F]

Answer 6

True

Question 7

All RDBMSs enforce integrity rules automatically[T/F]

Answer 7

False (Many RDBMS not all)

Question 8

Character data can contain any character or symbol intended for mathematical manipulation. [T/F]

Answer 8

False

Question 9

A data dictionary is sometimes described as “the database designer’s database” because it records the
design decisions about tables and their structures. [T/F]

Answer 9

True

Question 10

The order of the rows and columns is important to the DBMS.[T/F]

Answer 10

False

Question 11

Depending on the sophistication of the application development software with DBMS, nulls can create problems
when functions such as COUNT, AVERAGE, and SUM are used.[T/F]

Answer 11

True

Question 12

Because the relational model uses attribute values to establish relationships among tables, many
database users correctly assume that the term relation refers to such relationships. .[T/F]

Answer 12

False

Question 13

The practical significance of taking the logical view of a database is that it serves as a reminder of the
simple file concept of data storage. [T/F]

Answer 13

True

Question 14

Referential and entity integrity are two names for the same thing. [T/F]

Answer 14

False

Question 15

DBMSs use indexes for many different purposes.

Answer 15

True

Question 16

The relational database model enables you to view data ____ rather than ____.

Answer 16

logically, phisically

Question 17

____ data can have only a true or false (yes or no) values.

Answer 17

Logical

Question 18

A ____ key can be described as a superkey without nnecessary attributes, that is, a minimal superkey.

Answer 18

candidate

Question 19

Any attribute that is part of a key is known as a ____.

Answer 19

key attribute

Question 20

Referential ____ means that if the foreign key contains a value, that value refers to an existing valid
tuple (row) in another relation.

Answer 20

Integrity

Question 21

Controlled ____ makes a relational database work

Answer 21

redundancy

Question 22

A ____ is any key that uniquely identifies each row

Answer 22

superkey

Question 23

A(n) ____ is perceived as a two-dimensional structure composed of rows and columns.

Answer 23

table

Question 24

The relational model’s creator, E. F. Codd, used the term relation as a synonym for ____.

Answer 24

table

Question 25

A ____ key is defined as a key that is used strictly for data retrieval purposes.

Answer 25

secondary

Question 26

In the relational model, ____ are important because they are used to ensure that each row in a table is
uniquely identifiable

Answer 26

keys

Question 27

All primary key entries are unique, and no part of a primary key may be ____.

Answer 27

null

Question 28

A CUSTOMER table’s primary key is CUS_CODE. The CUSTOMER primary key column has no
null entries, and all entries are unique. This is an example of ____ integrity.

Answer 28

entity

Question 29

No data entry at all is known as a(n) ____.

Answer 29

null

Question 30

In the following table description, ____ is the primary key.
PRODUCT (PROD_CODE, PROD_DESCRIPT, PROD_PRICE, PROD_ON_HAND,
VEND_CODE)

Answer 30

PROD_CODE

Question 31

If one department chair—a professor—can chair only one department and one department can have
only one department chair, then the entities PROFESSOR and DEPARTMENT exhibit a(n)
____________________ relationship.

Answer 31

1:1

Question 32

The ____________________ catalog can be described as a detailed system data dictionary that
describes all objects within the database, including data about table names, the table’s creator and
creation date, the number of columns in each table, the data type corresponding to each column,
index filenames, index creators, authorized users, and access privileges.

Answer 32

system

Question 33

A(n) ____________________provides a detailed description of all tables found within the
user/designer-created database.

Answer 33

data dictionary

Question 34

In a relational table, each column has a specific range of values known as the
____________________ domain.

Answer 34

attribute

Question 35

The following example exhibits ____________________ integrity:
The CUSTOMER table’s primary key is CUS_CODE. The CUSTOMER primary key column has no
null entries, and all entries are unique. Similarly, the AGENT table’s primary key is AGENT_CODE,
and this primary key column also is free of null entries.

Answer 35

entity

Question 36

The purpose of the MAX function in SQL is to select a specific number of rows from a table. [T/F]

Answer 36

False

Question 37

The purpose of the MIN function in SQL is to return the maximum in a column of data. [T/F]

Answer 37

False

Question 38

The BETWEEN keyword is used in conjunction with the Order By clause to limit the number of rows returned in a query. [T/F]

Answer 38

False

Question 39

The purpose of the IN function in SQL is to select data that matches a set of values. [T/F]

Answer 39

True

Question 40

You cannot use aggregate functions in the WHERE clause of a SQL query because aggregate functions can only be used in the SELECT clause. [T/F]

Answer 40

True

Question 41

Functions that perform calculations on multiple rows of data and return a single result are called aggregate functions. [T/F]

Answer 41

True

Question 42

A nested query is a query that is contained within another query. [T/F]

Answer 42

True

Question 43

SELECT column1 FROM table1 WHERE column2 IN (SELECT column2 FROM table2) is a valid syntax. [T/F]

Answer 43

True

Question 44

The more important field in sorting two columns is called major sort key.[T/F]

Answer 44

True

Question 45

SELECT * FROM table ORDER BY column1 LIMIT 5, 10;
is a valid syntax for using the LIMIT clause in SQL [T/F]

Answer 45

True

Question 46

The WHERE keyword is used to create a nested query in SQL. [T/F]

Answer 46

True

Question 47

The purpose of DISTINCT function is to to return all unique values from a column. [T/F]

Answer 47

True

Question 48

The purpose of the COUNT function is too count the number of rows in a table or the number of non-null values in a column. [T/F]

Answer 48

True

Question 49

Basic Join is a type of join can be used in a nested query in SQL. [T/F]

Answer 49

True

Question 50

The GROUP BY statement comes after any WHERE statements, but before ORDER BY or LIMIT. [T/F]

Answer 50

True

Question 51

This function will display the current year:
EXTRACT(YEAR FROM curdate()); [T/F]

Answer 51

True

Question 52

The query statement below returns the average number of downloads for an app in our database.

SELECT AVE(DOWNLOADS)

FROM APPS; [T/F]

Answer 52

True

Question 53

The SUM aggregate function will you use when you include the asterisk(*) to represent all columns. [T/F]

Answer 53

False

Question 54

%M date formats will display the month name? [T/F]

Answer 54

True

Question 55

Comma (,) operators can be used in conjunction with the Order By clause to sort by multiple columns. [T/F]

Answer 55

True