Section 1 True* - Donutsdocshare01.docshare.tips/files/28468/284687836.pdf · True or False? True False 2. A Matrix Diagram will help you with all of the following except: Defining

Section 1

(Answer all questions in this section)

1. In the grid computing model,

resources are pooled together for

efficiency. True or False?

True*

False

2. The overall mission of the Oracle

Corporation is to use the internet and

fast servers to meet the needs of

organizations by only storing data.

True*

False

3. Which of the following are examples

of e-businesses that use database

software?

(Choose all correct answers)

Online clothing store*

Online book store*

Online personal web page

Online research paper

Online personal shopping service*

4. Personal computers (PCs) have

been in existence since 1950. True or

False?

True

False*

5. Users would use which of the

following software to access essential

business applications? (Choose three)


GUI Interface*

Internet Browser*

Server

Operating System*

6. Are all of the following examples of

how changes in computing have

affected day-to-day activities? Yes or

No?

In the past you used to use the phone

system to call directory assistance to

get a phone number. Today you can use

your PC to look up a phone number

online.

In the past you used to have to go to the

shoe store to buy shoes. Today you can

use your PC to order shoes online.

In the past you had to use your PC to

send a person an email. Today you can

use your phone to send a text message.

Yes*

No

7. Which of the following is NOT a type

of database?

Hierarchical

Relational

SQL*

Network

8. Databases function more efficiently

as:

Multiple applications on multiple client-

servers

Integrated software on fast processing

servers*

Client-based software on client-servers

Client-based software on personal

computers

Section 1

1. There is a big increase in

demand for Information Technology

professionals in today's market. True or

False? Mark for Review

True*

False

2. What are the major content

areas covered in the Oracle Academy?

Mark for Review

Database programming and Computer

repair.

SQL, database configuration and

performance tuning.

Data Modeling, SQL and PL/SQL*

Data Modeling, PJava and C+

3. Why is it important to

identify the business requirements

before beginning to program a new

system? Mark for Review

It is not important to have a blueprint

for database design and programs.

You should just start coding as soon

as possible, so you can meet your

deadlines.

It clarifies what a business wants to

accomplish, so that you can get your

database design and coding started

correctly.*

It allows application development to

be conducted without having to

consider database design.

It keeps businesses honest.

Section 1


1. Oracle was one of the first relational

database systems available

commercially? True or False?

True*

False

2. Data Modeling is the last stage in

the development of a database. True or

False?

True

False*

3. Which of the following is the correct

order for the Database Development

Process?

Strategy, Analysis, Design, Build*

Analysis, Strategy, Design, Build

Build, Strategy, Analysis, Design

Design, Build, Strategy, Analysis

Section 1

1. Which of the following are examples

of data vs. information.

A. Student age vs. average age of all

students in class

B. Bank deposit amount vs. total

account balance

C. Winning time for a race vs. length of

race

D. Price of computer vs. total sales of

all computers for a company

E. Both A and B*

2. What are the results of having all

your data in one central location?

(Choose two)


Improved performance*

Easier access to data*

Updates are harder to execute

Decreased performance

3. How do you turn "data" into

"information"?

By testing it

By querying it or accessing it

By storing it on a server

By storing it in a database

4. Consider an example where an

Oracle database works "behind the

scenes" for common internet activity.

Which of the following best describes a

database transaction?

A person searching an airline website to

find all available fares for a flight.*

A business identifies what processes it

uses for purchasing inventory.

A student places a link to their

homepage from the school's website.

A person looking in the newspaper for

good internet sites.

Section 2


1. Which of the following statements

are true about ERD's? (Choose Two)


A piece of information can be shown

multiple times on an ERD.

A piece of information should only be

found one place on an ERD.*

You should not model derivable data.*

All data must be represented on the

ERD, including derived summaries and

the result of calculations.

2. A well structured ERD will show only

some parts of the finished data model.

You should never try to model the entire

system in one diagram, no matter how

small the diagram might be. True or

False?

True

False*

3. An Entity Relationship model is

independent of the hardware or software

used for implementation. True or False?

True*

False

4. The purpose of an ERD is to

document the proposed system and

facilitate discussion and understanding

of the requirements captured by the

developer. True or False?

True*

False

Section 2


1. The word "Volatile" means....

Changing constantly; unstable*

Static; unlikely to change

Large quantity

Limited quantity

2. In the following statements, find two

examples of ENTITY: Instance. (Choose

Two)


DAIRY PRODUCT: milk*

VEGETABLE: grows

BOOK: Biography of Mahatma Gandhi*

TRAIN: runs


about attributes are true? (Choose Two)


They describe, qualify, quantify, classify,

or specify an entity.*

They are often adjectives.

They have a data type such as a

number or character string.*

They must be single valued unless they

belong to more than one entity.

4. What is the purpose of a Unique

Identifier?

To uniquely determine a table and

columns within that table.

To identify a specific column within a

table.

Create an entity that is unlike any other

entity aside from itself.

To identify one unique instance of an

entity, by using one or more attributes

and/or relationships.*

5. A/an _________ is a piece of

information that in some way describes

an entity. It is a property of the entity

and it quantifies, qualifies, classifies or

specifies the entity.

ERD

Process

Table

Attribute*

6. Some of the following could be

attributes of an ENTITY called PERSON.

Select the incorrect attributes for

PERSON. (Choose Two)


Age

Freddy Wilson*

Name

Priya Hansenna*

7. Unique Identifiers....

Distinguish one entity from another

Distinguish one instance of an entity

from all other instances of that entity*

Distinguish all entities in a database

Distinguishes nothing

8. Which of the following entities most

likely contains invalid attributes?

Entity: Home. Attributes: Number of

Bedrooms, Owner, Address, Date Built

Entity: Pet. Attributes: Name, Birthdate,

Owner

Entity: Car. Attributes: Owner*

Occupation, Owner Salary, Speed

Entity: Mother. Attributes: Name,

Birthdate, Occupation, Salary

9. In a physical data model, an

attribute is represented as a/an

Column*

Row

Instance

Foreign Key

10. Entities are usually verbs. True or

False?

True

False*

11. An entity may have which of the

following?

Experiences

Instances*

Tables

None of the above

12. All of the following would be

instances of the entity PERSON except

which?

David Jones

Male*

Angelina Rosalie

Grace Abinajam

Section 2


1. An Entity Relationship Diagram is an

example of a Physical Model. True or

False?

True

False*

2. Many reasons exist for creating a

conceptual model. Choose three

appropriate reasons from the options

below.


They model functional and informational

needs.*

They model the information flow of data.

They capture current and future needs.*

They accurately describe what a

physical model will contain.*

They capture implementation details of

a physical model.

3. A customized hat is an example of

the conceptual model or the physical

model?

Conceptual Model

Physical Model*

4. Which of the following are reasons

we create conceptual models?

It facilitates discussion. A picture is

worth a thousand words.

It forms important ideal system

documentation.

It takes into account government

regulations and laws

It forms a sound basis for physical

database design

All of the above*

5. Examples of software are:

Data entry webpages, Spreadsheets,

Google and Yahoo search Engines, SQL

Developer, Oracle Application Express*

Microsoft Word, Microsoft Powerpoint,

Microsoft Excel, Mouse pad

Mouse, Cables, Microsoft Word,

Microsoft Powerpoint

Monitor, Microsoft Word, Microsoft

PowerPoint, SQL Developer

6. Examples of hardware are:

Data entry web pages, Mouse, Hard

disk

Mouse, Hard disk, Monitor*

Monitor, Mouse, Printer, Printed Reports

Monitor, Mouse, Mouse pad, Cables and

Wires, Hard disk

Section 3

1. After looking at the diagram, choose

the sentence below that could be "read"

from the existing relationship (even

though you're missing relationship

labels!)

Each Student must have one or more

Activities.

Each Activity may be performed by one

or more Students .

Each Student may participate in one or

more Activities.*

Each Activity must belong to one and

only one Student.

2. Two entities can have one or more

relationships between them. True or

False?

True*

False

3. When reading a relationship between

2 entities, the relationship is only read

from left to right. True or False?

True

False*

Section 3

1. Creating a Matrix Diagram is

mandatory when doing Data Modeling.

True or False?

True

False

2. A Matrix Diagram will help you with

all of the following except:

Defining Relationships Between Entities*

Identifying Entities

Defining Instances of Entities

Naming Relationships

3. Matrix Diagrams helps verify you

have identified all possible relationships

between your existing entities. True or

False?

True

False

Section 3

1. Consider the recommended drawing

conventions for ERD's.

Indicate which of the following

accurately describes diagramming

conventions for entities and attributes:

The * means that an attribute is optional

and entity names should be plural verbs

The 'o' means that the attribute is

optional and entity names should be

plural verbs

The * means that an attribute is

mandatory or required and the entity

name should be singular*

The 'o' means that the attribute is

mandatory or required and the entity

name should be a singular noun

2. Attributes are written inside the

entity to which they belong. True or

False?

True*

False

3. Entity boxes are drawn as

Soft Boxes*

Hard Boxes

Bold Circles

Normal Circles

4. Entity names are always plural. True

or False?

True

False*

5. Which symbol is used to show that

a particular attribute is optional?

*

o*

#

&

6. On an ER diagram which symbol

identifies an attribute as part of a unique

identifier.

#*

*

o

x

Section 3


1. Relationships always exist between

3 or more entities

2 entities (or one entity twice)*

2 attributes

3 or more attributes

2. In a business that sells computers,

choose the best relationship name from

CUSTOMER to ITEM (computer, in this

case).

Each CUSTOMER must be the buyer of

one or more ITEMS.*

Each CUSTOMER must be the seller of

one or more ITEMS.

Each CUSTOMER may be the maker of

one or more ITEMS.

Each CUSTOMER may be the producer

of one or more ITEMS.

3. Relationships can be either

mandatory or optional. True or False?

True*

False

4. What are the three properties that

every relationship should have?

Transferability, degree, name

Name, optionality, degree*

A UID bar, a diamond, an arc

Name, optionality, arcs

Section 4


1. How should you handle constraints

that cannot be modeled on an ER

diagram?

Always let the network architect handle

them

List them on a separate document to

be handled programmatically*

Explain them to the users so they can

enforce them

All constraints must be modeled and

shown on the ER diagram

2. Business rules are important to data

modelers because:

A. They capture all of the needs,

processes and required functionality of

the business.*

B. They are easily implemented in the

ERD diagram.

C. The data modeler must focus on

structural rules, because they are easily

represented diagrammatically and

eliminate other rules that involve extra

procedures or programming.

D. Both A and C are true.

3. Which of the following is an example

of a structural business rule?

All employees must belong to at least

one department.*

Buildings to be purchased by the

business must be current with

earthquake building code.

All overdue payments will have an

added 10 % late fee.

All products will have a selling price no

less than 30 % greater than wholesale.

4. 'Only managers can approve travel

requests' is an example of which of the

following?

A structural business rule.

A mandatory business rule.

A procedural business rule.*

An optional business rule.

5. A business rule such as "All

accounts must be paid in full within 10

days of billing" is best enforced by:

Making the payment attribute

mandatory.

Making the relationship between

CUSTOMER and PAYMENT fully

mandatory and 1:1 on both sides.

Creating a message to be printed on

every bill that reminds the customer to

pay within ten days.

Hiring a programmer to create

additional programming code to identify

and report accounts past due.*

6. Why is it important to identify and

document business rules?

It allows you to create your data model

and then check it for accuracy.*

It allows you to improve the client's

business.

It ensures that the data model will

automate all manual processes.

None of the above

7. How would you model a business

rule that states that on a student's

birthday, they do not have to attend

their classes?

Use a supertype

Use a subtype

Make the attribute Birthdate mandatory

You cannot model this. You need to

document it*

Section 4


1. All instances of the supertype are

also instances of one of the subtypes.

True or False?

True*

False

2. All instances of the subtypes must

be an instance of the supertype. True or

False?

True*

False

3. Which of the following is true about

supertypes and subtypes?

Instances that belong to two subtypes of

the same supertype may be modeled as

a one-to-one relationship between the

two subtypes

Subtypes inherit the relationships and

attributes of the supertype.*

Subtypes may have no more than 2

levels of nesting.

Supertype and subtype entities must be

mutually exclusive

4. Which of the following is a TRUE

statement about the diagram below?

Every Z is either an A or a B

Every B is a Z

Every A is a Z

Every A is a B*

5. A subtype can have a relationship

not shared by the supertype. True or

False?

True*

False

6. A supertype should have at least

two subtypes. True or False?

True*

False

7. Which of the following is the best

scenario for using supertype/subtype

entities:

A pet store that sells small animals,

because they each need different size

cages and food.

An ice cream store that sells ice cream

in sugar cones and regular cones.

A grocery store that gives customers a

choice of plastic or paper bags.

A vehicle dealership that sells cars,

trucks and boats on trailers.*

8. The "Other" subtype is best used:

For instances that belong to the

supertype and at least one other

subtype.

For a subtype that does not have any of

the same attributes as the supertype to

which it belongs.

As an extra subtype to ensure that all

instances of subtypes are mutually

exclusive and complete. By having an

"Other" subtype, all instances of the*

Supertype will be of one subtype type.

You should never have a subtype called

Other.

Section 5


1. Non-transferable relationships can

only be mandatory, not optional. True or

False?

True*

False

2. If a relationship can be moved

between instances of the entities it

connects, it is said to be:

Implicit

Transferrable*

Committed

Recursive

3. A non-transferable relationship is

represented by which of the following

symbols?

Heart

Diamond*

Circle

Triangle

Section 5


1. What uncommon relationship is

described by the statements: "Each

LINE must consist of many POINTS and

each POINT must be a part of many

LINES"

One to Many Optional

One to Many Mandatory

Many to Many Optional

Many to Many Mandatory*

2. When resolving an M:M relationship,

the new relationships will always be ___

_______ on the many side.

Optional

Recursive

Mandatory*

Redundant

3. Which of the following are

relationship types? (Choose Two)


One to Some

Many to Many*

One to Many*

One to Another

4. Many to many relationships between

entities usually hide what?

Another relationship

Another entity*

More attributes

Uniqueness

5. Which of the following pairs of

entities is most likely to be modeled as

a M:M relationship? (Choose Two)


STUDENT and CLASS*

TREE and SEEDLING

PHONE NUMBER and SIM CARD

CAR and DRIVER*

6. If the same relationship is

represented twice in an Entity

Relationship Model, it is said to be:

Replicated

Removable

Redundant*

Resourceful

7. When are relationships

unnecessary?

When you can derive the relationship

from other relationships in the model*

When they have the same visual

structure but different meaning

When the information does not relate to

the model

When the relationships connect 2

entities and they each have distinct

meanings

Section 5


1. Many-to-Many relationships are

perfectly acceptable in a finished ERD.

There is no need to do any more work

on them. True or False?

True*

False

2. When you resolve a M-M by

creating an intersection entity, this new

entity will always inherit:

The attributes of both related entities.

A relationship to each entity from the

original M-M.*

The UID's from the entities in the

original M-M.

Nothing is inherited from the original

entities and relationship.

3. If an intersection entity is formed

that contains no attributes of its own, its

uniqueness may be modeled by

Creating new attributes.

Barring the relationships to the original

entities.*

Placing the UID attributes from the

original entities into the intersection

entity.

None of the above.

Section 6


1. What is the rule of Second Normal

Form?

All non-UID attributes must be

dependent upon the entire UID*

Some non-UID attributes can be

dependent on the entire UID

No non-UID attributes can be dependent

on any part of the UID

None of the Above

2. An entity can be on 2nd Normal

Form even if it has repeated values.

True or False?

True

False*

3. Examine the following entity and

decide which attribute breaks the 2nd

Normal Form rule:

ENTITY: CLASS

ATTRIBUTES:

CLASS ID

DURATION

SUBJECT

TEACHER NAME AND ADDRESS*

CLASS ID

DURATION

SUBJECT

Section 6


1. As a database designer it is your job

to store data in only one place and the

best place. True or False?

True*

False

2. Examine the following Entity and

decide which sets of attributes breaks

the 3rd Normal Form rule: (Choose Two)

ENTITY: TRAIN (SYNONYM: ROLLING

STOCK)

ATTRIBUTES:

TRAIN ID

MAKE

MODEL

DRIVER NAME

DEPARTURE STATION

NUMBER OF CARRIAGES

NUMBER OF SEATS

DATE OF MANUFACTURE


TRAIN ID, MAKE

DEPARTURE STATION, DRIVER NAME*

NUMBER OF CARRIAGES, NUMBER OF

SEATS*

MODEL, DATE OF MANUFACTURE

3. No databases in the world is ever

truly on 3rd Normal Form. Everyone

always stops after 2nd Normal Form.

True or False?

True

False*

Section 6


1. When data is stored in more than

one place in a database, the database

violates the rules of ___________.

Normalization*

Replication

Normalcy

Decency

2. When all attributes are single-

valued, the database model is said to

conform to:

1st Normal Form*

2nd Normal Form

3rd Normal Form

4th Normal Form

3. The following entity is on 1st normal

form: True or False?

ENTITY: VEHICLE

ATTRIBUTES:

REGISTRATION

MAKE

MODEL

COLOR

DRIVER

PASSENGER 1

PASSENGER 2

PASSENGER 3

True

False*

4. An entity can have repeated values

and still be in 1st Normal Form. True or

False?

True

False*

Section 6


1. An entity can only have one UID.

True or False?

True

False*

2. A UID can be made up from the

following: (Choose Two)


Attributes*

Entities

Relationships*

Synonyms

3. A unique identifier can only be made

up of one attribute. True or False?

True

False*

4. People are not born with "numbers,"

but a lot of systems assign student

numbers, customer IDs, etc. A shoe has

a color, a size, a style, but may not

have a descriptive "number". So, to be

able to uniquely and efficiently identify

one instance of the entity SHOE, a/an __

____________ UID can be created.

Artificial*

Unrealistic

Structured

Identification

Section 7


1. A relationship can be both recursive

and hierachal at the same time. True or

False?

True

False*

2. In this simple diagram, what

comprises the unique identifier for the

student class entity?

student id and class id

student id, class id and course id

course id

student id and course id*

3. A recursive rationship should not be

part of a UID. True or False?

True*

False

4. Which of the following would be a

good Unique Identifier for its Entity?

(Choose Two)


Identification Number for Person*

Birthdate for Baby Which Includes*

Hour, Minute, and Seconds

Order date for Order

Vehicle Type Number for Car

Section 7


1. If the entity CD has the attributes: #

number, *title, *producer, *year, o store

name, o store address, this entity is in

3rd Normal Form ("no non-UID attribute

can be dependent on another non-UID

attribute). True or False?

True

False*

2. This diagram could also be

expressed as a supertype/subtype

construction. True or False?

True

False*

3. Which of the following can be added

to a relationship?

An attribute

An arc can be assigned*

A composite attribute

An optional attribute can be created

4. Secondary UID's are

Not permitted in data modeling

Mandatory in data modeling

Useful as an alternative means*

identifying instances of an entity

Always comprised of numbers

5. Which of the following would best be

represented by an arc?

STUDENT (senior, junior)

STUDENT (graduating, non-graduating)

STUDENT (will-attend-university, will-

not-attend-university)

STUDENT ( University, Trade School)*

6. Which of the following is the

definition for Third Normal Form?

All attributes are single valued

An attribute must be dependent upon

entity's entire unique identifier

No non-UID attribute can be dependent*

on another non-UID attribute

All attributes are uniquely doubled and

independent

7. To visually represent exclusivity

between two or more relationships in an

ERD you would most likely use an _____

___.

Arc*

UID

Subtype

Supertype

8. All parts of a UID are mandatory.

True or False?

True*

False

Section 7


1. Historical data should always be

kept. True or False?

True

False*

2. Which of the following scenarios

should be modeled so that historical

data is kept? (Choose two)


LIBRARY and BOOK*

STUDENT and AGE

STUDENT and GRADE*

LIBRARY and NUMBER OF STAFF

3. Modeling historical data can

produce a unique identifier that includes

a date. True or False?

True*

False

4. Audit trail attributes cannot be

placed in the entities they are auditing,

they must be placed in separate, new

entities, created just for that purpose.

True or False?

True

False*

section 8

-----------------------------------------------------------------------------------------

Creating Tables

1.Once they are created, external tables

are accessed with normal SQL

statements? (True or False)

True (*)

False

2.Given this employee table: (employee_

id NUMBER(10) NOT NULL,

first_name VARCHAR2(25) NOT NULL,

last_name VARCHAR2(30) NOT NULL,

hire_date DATE DEFAULT sysdate)

What will be the result in the hire_date

column following this insert statement:

INSERT INTO employees VALUES (10,

'Natacha', 'Hansen', DEFAULT);

Statement will fail, as you must list the

columns into which you are inserting.

Statement will work and the hire_date

column will have the value of the date

when the statement was run. (*)

The character string SYSDATE.

The column for hire_date will be null.

3.CREATE TABLE bioclass

(hire_date DATE DEFAULT SYSDATE,

first_name varchar2(15),

last_name varchar2(15)); The above

CREATE TABLE statement is

acceptable, and will create a Table

named bioclass that contains a hire_

date,

first_name and last_name column. True

or False?

True (*)

False

4.When creating a new table, which of

the following naming rules apply:

(Choose three)

Must begin with a letter (*)

Can have the same name as another

object owned by the same user

Must contain ONLY A - Z, a - z, 0 - 9, _

(underscore), $, and # (*)

Must be an Oracle reserved word

Must be between 1 and 30 characters

long (*)

5.CREATE TABLE student_table

(id NUMBER(6),

lname VARCHAR(20),

fname VARCHAR(20),

lunch_num NUMBER(4)); Which of the

following statements best describes the

above SQL statement:

creates a table named student_table

with four columns: lname, fname, lunch,

num

creates a table named student with four

columns: id, lname, fname, lunch_num


with four columns: id, lname, fname,

lunch_num (*)


with four columns: lname, fname, lunch,

num

6. Examine this CREATE TABLE

statement: CREATE TABLE emp_load

(employee_number CHAR(5),

employee_dob CHAR(20),

employee_last_name CHAR(20),

employee_first_name CHAR(15),

employee_middle_name CHAR(15),

employee_hire_date DATE)

ORGANIZATION EXTERNAL

(TYPE ORACLE_LOADER

DEFAULT DIRECTORY def_dir1

ACCESS PARAMETERS

(RECORDS DELIMITED BY NEWLINE

FIELDS (employee_number CHAR(2),

employee_dob CHAR(20),

employee_last_name CHAR(18),

employee_first_name CHAR(11),

employee_middle_name CHAR(11),

employee_hire_date CHAR(10) date_

format DATE mask "mm/dd/yyyy“))

LOCATION ('info.dat'));

What kind of table is created here?

An external table with the data stored in

a file outside the database. (*)

A View.

An external table with the data stored in

a file inside the database.

None. This is in invalid statement.

7. I have a table named School_Friends

in my schema. You want to build a table

in your schema named School_Friends.

This is ______________, because ______

______________________________.

possible; my schema is separate from

yours, and it is okay for us to have like-

named tables in our separate schemas.

(*)

possible; our data will merge into one

table, and we can more easily access

our mutual friends information.

impossible; no matter what, there can

never be two tables with the same

name, even if they are in separate

schemas.

impossible; School_Friends is a

reserved term in SQL.

8. DCL, which is the acronym for Data

Control Language, allows:

the ALTER command to be used.

a Database Administrator the ability to

grant privileges to users. (*)

the TRUNCATE command to be used.

the CONTROL TRANSACTION statement

can be used.

9. It is possible to create a table by

using the CREATE TABLE command in

conjunction with a subquery. True or

False?

True (*)

False

-----------------------------------------------------------------------------------------

Using Data Types

1. To store large amounts of text you

should simply create a series of

VARCHAR2 columns in a table. True or

False?

True

False (*)

2. Which of the following are valid

Oracle datatypes?

DATE, BLOB, LOB, VARCHAR2

DATE, TIMESTAMP WITH LOCAL

TIMEZONE, BLOB (*)

TIMESTAMP, LOB, VARCHAR2,

NUMBER

SYSDATE, TIMESTAMP, DATE, LOCAL

TIMEZONE

3.The BLOB datatype can hold a

maximum of 128 Terabytes of data.

True or False?

True (*)

4.INTERVAL DAY TO SECOND stores a

period of time in terms of days, hours,

minutes, and seconds. True or False?

True (*)

False

-----------------------------------------------------------------------------------------

Modify a table

1.To completely get rid of a table, its

contents, its structure, AND release the

storage space the keyword is:

DROP (*)

DELETE

TRUNCATE

KILL

2. The following code creates a table

named student_table with four columns:

id, lname, fname, lunch_num CREATE

TABLE student_table

(id NUMBER(6),

lname VARCHAR(20),

fname VARCHAR(20),

lunch_num NUMBER(4));

The lunch_num column in the above

table has been marked as UNUSED.

Which of the following is the best

statement you can use if you wish to

remove the UNUSED column from the

student_table?

DROP column

ALTER TABLE DELETE UNUSED

COLUMNS

ALTER TABLE DROP UNUSED

COLUMNS (*)

ALTER TABLE DELETE ALL COLUMNS

3. You can use DROP COLUMN to drop

all columns in a table, leaving a table

structure with no columns. True or

False?

True

False (*)

4.Which of the following will correctly

change the name of the LOCATIONS

table to NEW_LOCATIONS?

ALTER TABLE LOCATIONS RENAME

NEW_LOCATIONS

MODIFY TABLE LOCATIONS RENAME

NEW_LOCATIONS

RENAME LOCATIONS TO NEW_

LOCATIONS (*)

None of the above; you cannot rename

a table, you can only CREATE, ALTER

and DROP a table.

5.When should you use the SET

UNUSED command?

Never, there is no SET UNUSED

command

You should use it if you think the

column may be needed again later

You should use it when the system is

being heavily used (*)

You should only use this command if

you want the column to still be visible

when you DESCRIBE the table

6. Comments can be added to a table

by using the COMMENT ON TABLE

statement. The comments being added

are enclosed in:

Double quotes " "

Single quotes ' ' (*)

Parentheses ( )

Brackets { }

7. You can use the ALTER TABLE

statement to:

Add a new column

Modify an existing column

Drop a column

All of the above (*)

8. When you use ALTER TABLE to add

a column, the new column:

Becomes the first column in the table

Becomes the last column in the table (*)

Can be placed by adding a GROUP BY

clause

Will not be created because you cannot

add a column after the table is created

9. ALTER TABLE table_name RENAME

can be used to:

Rename a row.

Rename a column.

Rename a table. (*)

All of the above.

10. The FLASHBACK TABLE to BEFORE

DROP can restore only the table

structure, but not its data back to before

the table was dropped. True or False?

True

False (*)

11. After issuing a SET UNUSED

command on a column, another column

with the same name can be added using

an ALTER TABLE statement. True or

False?

True (*)

False

12. The FLASHBACK QUERY statement

can restore data back to a point in time

before the last COMMIT. True or False?

True

False (*)

13.A column?s data type can always be

changed from NUMBER to VARCHAR2

but not from VARCHAR2 to NUMBER,

provided the table is empty. True or

False?

True

False (*)

14. The data type of a column can

never be changed once it has been

created. True or False?

True

False (*)

Section 9


1. Which of the following would be a

logical constraint when modeling time

for a country entity?

People have births and deaths in their

countries that must be tracked by the

system.*

If you are doing a system for France or

Germany, you would need security

clearance.

Countries may need an end date in

your system, because they can change

fundamentally over time, e.g.

Yugoslavia.

You need a constant record of countries,

because they are still countries, even if

leadership changes over time, e.g.

France, USA and most other countries.

2. When you add the concept of time to

your data model, you are:

Simplifying your model.

Adding complexity to your model.*

Just changing the model, but this does

not change the complexity of it.

None of the above.

3. It is desirable to have an entity

called DAY with a holiday attribute when

you want to track special holidays in a

payroll system. True or False?

True*

False

4. Modeling historical data produces

efficient ways for a business to operate

such as:

Modeling historical data does not help a

business.

Providing valuable information via

reports to management .*

Keeping track of holiday dates.

Employees can work in two time zones.

5. What is the benefit to the users of a

system that includes "time," e.g. Start

Date and End Date for Employees?

Increased usability and flexibility of a

system; we can the trace e.g. the

different managers an employee had

over time.*

System becomes 100% unstable; allows

users to log on and log off at will.

Users are able to create complex

programs in support of this component.

Reporting becomes nearly impossible,

users enjoy this.

6. If you are tracking employment

dates for an employee, do you need to

have an "End Date" attribute?

Yes, because you always need an end

date when you have a start date

No, because an end date is usually

redundant

Yes, if the company wants to track

employee information, like multiple start

and end dates*

No, not if the company likes the

employee

7. How do you know when to use the

different types of time in your design?

The rules are fixed and should be

followed

It depends on the functional needs of

the system*

You would first determine the existence

of the concept of time and map it

against the Greenwich Mean Time

Always model time, you can take it out

later if it is not needed

Section 9


1. What is the function of logging or

journaling in conceptual data models?

Allows you to track the history of*

attribute values, relationships and/or

entire entities

Gives a timestamp to all entities

Represents entities as time in the data

model

Creates a fixed time for all events in a

data model

2. Which of the following is a logical

constraint that could result from

considering how time impacts an

example of data storage?

End Date must be before the Start Date.

ASSIGNMENT periods can overlap

causing the database to crash.

An ASSIGNMENT may only refer to a

COUNTRY that is valid at the Start Date

of the ASSIGNMENT.*

Dates can be valued only with Time.

3. Why would you want to model a

time component when designing a

system that lets people buy bars of

gold?

The price of gold fluctuates and for

determining price, you need to know the

time of purchase*

To allow the sales people to determine

where the gold is coming from

You would not want to model this, it is

not important

The Government of your country might

want to be notified of this transaction.

4. You are doing a data model for a

computer sales company, where the

price goes down on a regular basis. If

you want to allow them to modify the

price and keep track of the changes,

what is the best way to model this?

A. Create a product entity and a related

price entity with start and end dates,

and then let the users enter the new

price whenever required.

B. Create a new item and a new price

every day.

C. Use a price entity with a start and

end date

D. Allow them to delete the item and

enter a new one.

E. Both A and C*

Section 10

1. There are no formal rules for how to

draw ERD's. The most important thing

is to make sure all entities, attributes

and relationships are documented on

diagram. The Layout is not significant.

True or False?

True

False*

2. It is a good idea to group your

entities in a diagram according to the

expected volumes. By grouping high

volume entities together, the diagrams

could become easier to read. True or

False?

True*

False

3. You must make sure all entities of a

proposed system can fit onto one

diagram. It is not allowed to break up a

data model into more than one diagram.

True or False?

True

False*


are true for ERD's to enhance their

readability. (Choose Two)


There should be no crossing lines.*

All crows feet (Many-ends) of

relationships should point the same

way.*

There should be many crossing lines

It does not matter which way the crows

feet (many ends) point.

Section 10


1. All data models MUST have some

portions of the model modeled as a

generic component. True or False?

True

False*

2. Generic models are generally less

complex than a specific model. True or

False?

True

False*

3. When you transform a specific

model to be generic, which of the

following statements are true? (Choose

Two)


You tend to end up with fewer entities

in the generic model than you had in the

specific model*

Either all or none of the original*

attributes make it into the generic

model.

You will always have more entities in a

generic model than in the corresponding

specific model.

None of the original specific model

attributes are allowed model

Section 11


1. When mapping supertypes,

relationships at the supertype level

transform as usual. Relationships at

subtype level are implemented as

foreign keys, but the foreign key

columns all become optional. True or

False?

True*

False

2. When translating an arc relationship

to a physical design, you must turn the

arc relationships into foreign keys.

What additional step must you take

with the created foreign keys to ensure

the exclusivity principle of arc

relationships? (Assume that you are

implementing an Exclusive Design)

(Choose Two)


Make all relationships mandatory

Make all relationships optional*

Create an additional check constraint

to verify that one foreign key is*

populated and the others are not

All the above

3. Which of the following are reasons

you should consider when using a

Subtype Implementation?


When the common access paths for the

subtypes are similar.

When the common access paths for

the subtypes are different.*

Business functionality and business

rules are similar between subtypes.

Most of the relationships are at the

subtype level*

4. The "Arc Implementation" is a

synonym for what type of

implementation?

Supertype Implementation

Subtype Implementation

Cascade Implementation

Supertype and Subtype*

Implementation

Section 11


1. In a physical data model, an entity

becomes a _____________.

Attribute

Table*

Constraint

Column

2. Why would this table name NOT work

in an Oracle database?

2007_EMPLOYEES

Numbers cannot be incorporated into

table names

Table names must start with an

alphabetic character*

Underscores "_" are not allowed in table

names

None of the above

3. In an Oracle database, why would

the following table name not be allowed

'EMPLOYEE JOBS'?

The database does not understand all

capital letters

EMPLOYEE is a reserved word

JOBS is a reserved word

You cannot have spaces between

words in a table name*

4. Attributes become columns in a

database table. True or False?

True*

False

5. The transformation from an ER

diagram to a physical design involves

changing terminology. Relationships in

the ER diagram become __________ ,

and primary unique identifiers become

____________.

Foreign keys, primary keys*

Primary keys, foreign keys

Foreign keys, mandatory business rules

Foreign keys, optional business rules

6. In a physical data model, a

relationship is represented as a:

Column

Primary Key

Unique Identifier

Foreign Key*

7. The transformation from an ER

diagram to a physical design involves

changing terminology. Entities in the

ER diagram become __________ , and

attributes become ____________.

Columns, Tables

Tables, Columns*

Foreign Keys, Columns

Tables, Foreign Keys

Section 11


1. Two entities A and B have an

optional (A) to Mandatory (B) One-to-

One relationship. When they are

transformed, the Foreign Key(s) is

placed on:

The table B*

The table A

Nowhere, One-to-One are not

transformed

Both tables A and B get a new column

and a Foreign Key.

2. One-to-One relationships are

transformed into Foreign Keys in the

tables created at either end of that

relationship? True or False?

True

False*

3. What do you create when you

transform a many to many relationship

from your ER diagram into a physical

design?

Foreign key constraints

Intersection entity

Intersection table*

Primary key constraints

4. A barrred Relationship will result in

a Foreign Key column that also is part

of:

The Table Name

The Column Name

The Check Constraint

The Primary Key*

5. Relationships on an ERD can only

be transformed into UIDs in the physical

model? True or False?

True

False*

6. One-to-Many Optional to

Mandatory becomes a _______________

on the Master table.

Mandatory Foreign Key

Nothing (There are no new columns

created on the Master table)*

Optional Foreign Key

Primary Key

Section 11


1. Column integrity refers to

Columns always having values

Columns always containing positive

numbers

Columns always containing values

consistent with the defined data format*

Columns always containing text data

less than 255 characters

2. One or more columns in a primary

key can be null. True or False?

True

False*

3. The explanation below is an example

of what constraint type:

The value in the dept_no column of the

EMPLOYEES table must match a value

in the dept_no column in the

DEPARTMENTS table.

Entity integrity

Referential integrity*

Column integrity

User-defined integrity

4. A foreign key always refers to a

primary key in the same table. True or

False?

True

False*

5. Foreign keys cannot be null when

It is part of a primary key*

It refers to another table

It contains three or more columns

6. A table does not have to have a

primary key. True or False?

True*

False

7. The explanation below defines which

constraint type:

A primary key must be unique, and no

part of the primary key can be null.

Entity integrity*

Referential integrity

Column integrity


8. Identify all of the correct

statements that complete this

sentence: A primary key is ...(Choose

Three)


A single column that uniquely identifies

each row in a table*

A set of columns that uniquely

identifies each row in a table*

A set of columns and keys in a single

table that uniquely identifies each row in

a single table*

Only one column that cannot be null

9. The explanation below defines which

constraint type:

A column must contain only values

consistent with the defined data format

of the column

Entity integrity


Column integrity*


10. The explanation below is an

example of what constraint type:

If the value in the balance column of

the ACCOUNTS table is below 100, we

must send a letter to the account owner

which will require extra programming to

enforce.

Entity integrity


Column integrity

User-defined integrity*

Documents

Section 1 True* - Donutsdocshare01.docshare.tips/files/28468/284687836.pdf · True or False? True False 2. A Matrix Diagram will help you with all of the following except: Defining