Deck 2: Database Design Fundamentals

Question 1

In an entity-relationship (E-R) diagram, one-to-many relationships between entities are drawn as _____.

A) rectangles
B) equals signs between shapes
C) lines between shapes
D) circles

Answer 1

C

Question 2

The process of determining the particular tables and columns that will comprise a database is known as _____.

A) normalization
B) database design
C) qualification
D) relational management

Answer 2

B

Question 3

A property of an entity is _____.

A) like a noun
B) an attribute
C) a table row
D) its association with other entities

Answer 3

B

Question 4

Why have Social Security numbers traditionally been used as primary keys for database tables that store personal data on individual people?

A) All other columns in such a table are functionally dependent on the Social Security number column.
B) The Social Security number is always the only candidate key in such a table.
C) A Social Security number column is functionally dependent on all the other columns in such a table.
D) The Social Security number is functionally independent of most other columns in such a table.

Question 5

A determinant is any column (or collection of columns) that determines another table.

Question 6

A relation that does not contain any repeating groups is in _____.

A) first normal form
B) second normal form
C) third normal form
D) Boyce-Codd normal form

Question 7

In a relational database, _____.

A) rows must be ordered numerically
B) relations must include repeating groups
C) columns should be ordered correctly
D) each row should be unique

Question 8

A relational database _____.

A) consists of relationships between entities
B) implements relationships through common table rows
C) consists of tables called relations
D) implements relationships through repeating groups

Question 9

One can successfully design a database system without fully understanding the concept of functional dependence.

Question 10

In this text, Boyce-Codd normal form is the same as _____.

A) unnormalized
B) first normal form
C) second normal form
D) third normal form

Question 11

Suppose you have a table with a primary key composed of two columns. When another column in this table is dependent on only one of the two columns in the primary key, this poses a risk for _____.

A) qualification errors
B) update anomalies
C) function splitting
D) functional dependency

Question 12

When the commonly accepted shorthand representation is used to describe a database, _____.

A) each column name appears on its own line
B) the first attributes from each row are listed in parentheses
C) tables cannot contain columns with duplicate names
D) it is always acceptable to qualify column names

Question 13

You can determine functional dependence by viewing sample data.

Question 14

In an entity-relationship (E-R) diagram, tables are represented by _____.

A) rectangles
B) ovals
C) circles
D) diamonds

Question 15

Which statement describing relations is false?

A) A relation is a two-dimensional table.
B) The entries in a relation may be single- or double-valued.
C) Each column in a relation has a distinct name.
D) The order of the columns in a relation is immaterial.

Question 16

The duplication of data is formally called _____.

A) a repeating group
B) redundancy
C) replication
D) an anomaly

Question 17

If column A in a relational database determines a single value for column B at any point in time, then column B is functionally dependent on column A.

Question 18

Which statement regarding primary keys is true?

A) By definition, a primary key always consists of a single column.
B) You can identify primary keys for tables by examining sample data.
C) Some tables include more than one column that can be used as a primary key.
D) All primary keys are values generated by database software.

Question 19

One of the categories of update anomalies is _____.

A) functional dependencies
B) functional splits
C) inconsistent data
D) qualifications

Question 20

The statement "A sales rep's pay class functionally determines his or her pay rate" means that if you know the pay class, you can determine the pay rate.

Question 21

Diamonds are sometimes used in E-R diagrams to _____.

A) identify the names of entities in a database
B) indicate which entity is on the "many" side of a one-to-many relationship
C) represent individual tables
D) describe the relationship between two tables

Question 22

James converts a table with this notation: INVOICES (INVOICE_NUM, INVOICE_DATE, (ITEM_ID, QUANTITY))
Into a table with this notation:
INVOICES (INVOICE_NUM, INVOICE_DATE, ITEM_ID, QUANTITY)
James has _____.

A) made the table design worse
B) converted a table in first normal form into a table in second normal form
C) converted an unnormalized relation into a table in first normal form
D) added a repeating group to a table

Question 23

A table in second normal form should be improved to third normal form because _____.

A) its determinants can cause update anomalies
B) its candidate keys can cause update anomalies
C) this reduces the number of relations in the database
D) this eliminates repeating groups that waste space

Question 24

Which of the following tables is in third normal form, given that DOC_ID determines DOC_FIRST_NAME and DOC_LAST_NAME?

A) PATIENT (PATIENT_ID, FIRST_NAME, LAST_NAME, DOC_ID, DOC_FIRST_NAME, DOC_LAST_NAME)
B) PATIENT (PATIENT_ID, FIRST_NAME, LAST_NAME, VISIT_DATE, (SERVICE, BILLING_CODE))
C) PATIENT (PATIENT_ID, FIRST_NAME, LAST_NAME, EMAIL, PHONE_NO, DOC_ID)
D) PATIENT (PATIENT_ID, DOC_ID, FIRST_NAME, LAST_NAME, (ADMIT_DATE, RELEASE_DATE))

Question 25

What is the precise definition of a primary key?

Question 26

Within an entity-relationship diagram, which of the following would indicate that the relationship between A and B is one (A) to many (B)?

A) An arrow drawn from rectangle B points to rectangle A.
B) A line drawn from rectangle A ends in a crow's foot at rectangle B.
C) A line with a number 1 beside it is drawn from rectangle A to rectangle B.
D) A line with a letter n beside it is drawn from a diamond to rectangle A.

Question 27

How does a database management system that follows the relational model handle entities, attributes of entities, and relationships between entities?

Question 28

Explain why and how an unnormalized relation should be converted into a relation in first normal form.

Question 29

You receive the following requirements for a caterer's database: For a customer, store a customer ID, last name, first name, billing address, and phone number
For an order, store an order number, order date, event date, customer ID, description of services, and total price for services
When designing this database, which step do you take first?

A) Identify the customer ID and order number as unique identifiers.
B) Identify and name the entities CUSTOMER and ORDER.
C) Identify customer ID, last name, first name, billing address, and phone number as attributes.
D) Create a CUSTOMER table that includes all the customers' attributes as columns.

Question 30

You are working with a QUOTATIONS table that contains no repeating groups and has a primary key consisting of the SERVICE_CODE and SPECS columns. You realize that some other columns in the table functionally depend on either SERVICE_CODE or SPECS, but not both, whereas the rest depend on both. How should you improve this table?

A) remove the multiple entries from the SERVICE_CODE and SPECS columns
B) eliminate any columns that determine other columns from the table
C) combine SERVICE_CODE and SPECS into a single-column primary key
D) replace it with three tables with the following primary keys: SERVICE_CODE, SPECS, and SERVICE_CODE plus SPECS

Question 31

When you are designing a database, _____.

A) you might be able to determine the relationships between tables directly from the requirements
B) one useful approach to identifying relationships between tables is to look for matching rows
C) the many part of a relationship between tables occurs where the matching column is the primary key
D) attributes with functional dependencies should not be placed together in the same table

Question 32

When you convert an unnormalized table to a table in first normal form, the primary key of the table in first normal form _____.

A) rarely includes a column from the repeating group
B) is usually the primary key of the unnormalized table concatenated with the key for the repeating group
C) rarely includes the primary key of the unnormalized table
D) is usually exactly the same as the primary key of the unnormalized table

Question 33

In the following shorthand representation of a database, the underlined items are _____. INVOICES (INVOICE_NUM, INVOICE_DATE, CUST_ID)
INVOICE_LINE (INVOICE_NUM, ITEM_ID, QUANTITY, QUOTED_PRICE)
ITEM (ITEM_ID, DESCRIPTION, ON_HAND, CATEGORY, LOCATION, PRICE)

A) relations
B) entities
C) nonkey columns
D) primary keys