Halaman

Wednesday, August 7, 2019

Database Design Final Exam

Database Design Final Exam


Examine the following entity and decide which attribute breaks the 2nd Normal Form rule:
ENTITY: RECEIPT
ATTRIBUTES:
   #CUSTOMER ID
   #STORE ID
   STORE LOCATION
   DATE
   
                                                                            
                                               
                STORE LOCATION (*)

                                               
                CUSTOMER ID

                                               
                STORE ID

                                               
                DATE

                                                                               
When is an entity in 2nd Normal Form? 
       
                                               
                When all non-UID attributes are dependent upon the entire UID. (*)

                                               
                When attributes with repeating or multi-values are present.

                                               
                When no attritibutes are mutually independent and all are fully dependent on the primary key.

                                               
                None of the Above.

                                                                               
To resolve a 2nd Normal Form violation, we:      
                                                                               
                                               
                Move the attribute that violates 2nd Normal Form to a new ERD.

                                               
                Move the attribute that violates 2nd Normal Form to a new entity with a relationship to the original entity. (*)

                                               
                Delete the attribute that was causing the violation.

                                               
                Do nothing, an entity does not need to be in 2nd Normal Form.

                                                                               
When all attributes are single-valued, the database model is said to conform to:             
                                               
                4th Normal Form

                                               
                1st Normal Form (*)

                                               
                3rd Normal Form

                                               
                2nd Normal Form

                                                                               
An entity ORDER has the attributes Order ID, Order Date, Product id, Customer ID. This entity is in 1st Normal Form. True or False?    
                                                                               
                                               
                True

                                               
                False (*)

To convert an entity with a multi valued attribute to 1st Normal Form, we create an additional entity and relate it to the original entity with a 1:1 relationship. True or False?
                                                                               
                                               
                True

                                               
                False (*)

                                                                               
When data is stored in more than one place in a database, the database violates the rules of ___________.
                                                                               
                                               
                Normalcy

                                               
                Replication

                                               
                Decency

                                               
                Normalization (*)

                                                                               
Examine the following Entity and decide which sets of attributes break the 3rd Normal Form rule:
ENTITY: TRAIN
ATTRIBUTES:
    TRAIN ID
    MAKE
    DRIVER ID
    DRIVER NAME
    DATE OF MANUFACTURE
                                                                               
                                               
                TRAIN ID, MAKE

                                               
                DRIVER ID, DRIVER NAME (*)

                                               
                MAKE, DATE OF MANUFACTURE

                                               
                None of the above, the entity is already in 3rd Normal Form.

                                                                               
Examine the following Entity and decide which rule of Normal Form is being violated:
ENTITY: CLIENT
ATTRIBUTES:
    # CLIENT ID
    FIRST NAME
    LAST NAME
    ORDER ID
    STREET
    ZIP CODE
                                                                               
                                               
                1st Normal Form. (*)

                                               
                2nd Normal Form.

                                               
                3rd Normal Form.

                                               
                None of the above, the entity is fully normalised.

                                                                               
As a database designer, you do not need to worry about where in the datamodel you store a particular attribute; as long as you get it onto the ERD, your job is done. True or False?
                                               
                True

                                               
                False (*)

When any attribute in an entity is dependent on any other non-UID attribute in that entity, this is known as:  
                                                                               
                                               
                Non-dependency

                                               
                Transitive dependency (*)

                                               
                Functional dependency

                                               
                Dependency

                                                                               
 A unique identifier can only be made up of one attribute. True or False?           
                                               
                True

                                               
                False (*)

                                                                               
A UID can be made up from the following: (Choose Two)        
                                                                               
                                               
                Relationships (*)

                                               
                Synonyms

                                               
                Entities

                                               
                Attributes (*)

                                                                               
A candidate UID that is not chosen to be the Primary UID is called:        
                                               
                Artificial

                                               
                Secondary (*)

                                               
                Simple

                                               
                Composite

                                                                               
If an entity has no attribute suitable to be a Primary UID, we can create an artificial one. True or False?                                                                      
                                               
                True (*)

                                               
                False

Arcs are Mandatory in Data modeling. All ERD's must have at least one Arc. True or False?                                                                
                                               
                True

                                               
                False (*)

                                                                               
Which of the following can be added to a relationship?  
                                                                               
                                               
                An attribute

                                               
                An optional attribute can be created

                                               
                A composite attribute

                                               
                An arc can be assigned (*)

                                                                               
Arcs are used to visually represent _________ between two or more relationships in an ERD.                                                                    
                                               
                Inheritance

                                               
                Exclusivity (*)

                                               
                Sameness

                                               
                Differences

                                                                               
All relationships participating in an arc must be mandatory. True or False?           
                                               
                True

                                               
                False (*)

                                                                               
Cascading UIDs are a feature often found in what type of Relationship? 
                                                                               
                                               
                General Relationship

                                               
                Invalid Relationship

                                               
                Recursive Relationship

                                               
                Heirarchical Relationship (*)

A Hierarchical relationship is a series of relationships that reflect entities organized into successive levels. True or False?  
                                                                               
                                               
                True (*)

                                               
                False

                                                                               
A relationship between an entity and itself is called a/an:       
                                               
                Recursive Relationship (*)

                                               
                Heirarchical Relationship

                                               
                Invalid Relationship

                                               
                General Relationship

                                                                               
A Recursive Relationship is represented on an ERD by a/an:       
                                                                               
                                               
                Single Toe

                                               
                Crow's Foot

                                               
                Dog's Tail

                                               
                Pig's Ear (*)

                                                                               
A particular problem may be solved using either a Recursive Relationship or a Hierarchical Relationship, though not at the same time. True or False?           
                                                                               
                                               
                True (*)

                                               
                False

                                                                               
Which of the following would be a logical constraint when modeling time for a City entity?               
                                                                               
                                               
                If you are doing a system for any French City, you would need security clearance.

                                               
                People are born in the city and people die in the city.

                                               
                Cites may change their names and/or country association if the borders of a country change. (*)

                                               
                Daily traffic patterns must be monitored to determine how many law enforcement officers are needed.

Modeling historical data is optional. True or False?      
                                                                               
                                               
                True (*)

                                               
                False

                                                                               
Which of the following scenarios should be modeled so that historical data is kept? (Choose two)     
                                                                               
                                               
                CUSTOMER and PAYMENTS (*)

                                               
                CUSTOMER and ORDERS (*)

                                               
                TEACHER and AGE

                                               
                BABY and AGE

                                                                               
Which of the following scenarios should be modeled so that historical data is kept? (Choose two)     
                                                                               
                                               
                STUDENT and GRADE (*)

                                               
                LIBRARY and NUMBER OF BOOKS

                                               
                STUDENT and AGE

                                               
                LIBRARY and BOOK (*)

                                                                               
Why would you want to model a time component when designing a system that lets people buy bars of gold?          
                                                                               
                                               
                Sales people must determine where the gold is coming from.

                                               
                You would not want to model this; it is not important.

                                               
                The price of gold fluctuates and, to determine the current price, you need to know the time of purchase. (*)

                                               
                The Government of your country might want to be notified of this transaction.

                                                                               
You are doing a data model for a computer sales company where the price of postage depends upon the day of the week that goods are shipped. So shipping is more expensive if the customer wants a delivery to take place on a Saturday or Sunday. What would be the best way to model this?   
                                                                               
                                               
                Update the prices in the system, print out the current prices when they change, and pin them on the company noticeboard.

                                               
                Email current prices to all employees whenever a price changes.

                                               
                Use a Delivery Day entity, which holds prices against week days, and ensure the we also have an attribute for the Requested Delivery Day in the Order Entity. (*)

                                               
                Allow them to enter whatever delivery charge they want.

In an ERD, High Volume Entities usually have very few relationships to other entities. True or False?     
                                                                               
                                               
                True

                                               
                False (*)

                                                                               
 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 (*)

                                                                               
 The explanation below is an example of which constraint type?
A primary key must be unique, and no part of the primary key can be null.           

                                               
                Entity integrity (*)

                                               
                User-defined integrity

                                               
                Referential integrity

                                               
                Column integrity

                                                                               
A foreign key always refers to a primary key in the same table. True or False?    
                                               
                True

                                               
                False (*)

                                                                               
                                                               
Identify all of the incorrect statements that complete this sentence: A primary key is...(Choose three)  
                                                                               
                                               
                One or more columns in a table that uniquely identifies each row in that table.

                                               
                A single column that uniquely identifies each column in a table. (*)

                                               
                Only one column that must be null. (*)

                                               
                A set of columns in one table that uniquely identifies each row in another table. (*)

The explanation below is an example of which 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.     
                                               
                Column integrity

                                               
                Entity integrity

                                               
                Referential integrity (*)

                                               
                User-defined integrity

                                                                               
A table must have a primary key. True or False? 
                                               
                True

                                               
                False (*)

                                                                               
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 mandatory. True or False?   
                                                                               
                                               
                True

                                               
                False (*)

                                                                               
Which of the following is a valid reason for considering a Subtype Implementation?        
                                                                               
                                               
                The common access paths for the supertypes are different.

                                               
                The resulting table will reside in a single database and be used by just ONE user.

                                               
                Most of the relationships are at the supertype level.

                                               
                Business functionality, business rules, access paths, and frequency of access are all very different between the subtypes. (*)

                                                                               
In an Oracle database, why would the following table name not be allowed 'EMPLOYEE JOBS'?  
                                                                               
                                               
                JOBS is a reserved word

                                               
                The database does not understand all capital letters

                                               
                You cannot have spaces between words in a table name (*)

                                               
                EMPLOYEE is a reserved word


In a physical data model, a relationship is represented as a:      
                                               
                Primary Key

                                               
                Foreign Key (*)

                                               
                Column

                                               
                Unique Identifier

                                                                               
Why would this table name NOT work in an Oracle database? this_year_end+next_year                          
                                               
                Table names must begin with an alphabetic character.

                                               
                It is too long.

                                               
                The Plus sign + is not allowed in object names. (*)

                                               
                None of the above.

                                                                               
The transformation from an ER diagram to a physical design involves changing terminology. Entities in the ER diagram become __________ :       
                                               
                Columns

                                               
                Foreign Keys

                                               
                Unique Keys

                                               
                Tables (*)

                                                                               
One-to-One relationships are transformed into Foreign Keys in the tables created at either end of that relationship. True or False?
                                                                               
                                               
                True

                                               
                False (*)

                                                                               
In a physical model, many to many relationships are resolved via a structure called a(n): ________________   
                                                                               
                                               
                Intersection Entity

                                               
                Subtype

                                               
                Intersection Table (*)

                                               
                Supertype

Relationships on an ERD can only be transformed into UIDs in the physical model? True or False?    
                                                                               
                                               
                True

                                               
                False (*)

                                                                               
An Arc is transformed to the physical model by adding a foeign Key for every relationship in the Arc. True or False? 
                                                                               
                                               
                True (*)

                                               
                False

                                                                               
A barrred Relationship will result in a Foreign Key column that also is part of:     
                                                                               
                                               
                The Check Constraint

                                               
                The Primary Key (*)

                                               
                The Column Name

                                               
                The Table Name

                                                                               
In which phases of the System Development Life Cycle will we need to use SQL as a language? (Choose Two)  
                                                                               
                                               
                Transition (*)

                                               
                Build and Document (*)

                                               
                Strategy

                                               
                Analysis


The data model can be used to...     
                                                                               
                                               
                Communicate and confirm

                                               
                Describe and specify

                                               
                Analyze and refine

                                               
                All of the Above (*)

No comments:

Post a Comment

Final Exam Java Programming 2019 Learner - English

Final Exam