Modeling Final Questions

True or False, any change to an object's attributes will always result in a state change of the object? A) True B) False

A is incorrect. A change in an object's attribute does not always result in a state change B is correct. The attributes or properties of an object can have an effect on the object's state but not all attributes are significant enough to change it.

A relation is normalized through 3rd Normal Form (3NF) if... A) There are no transitive functional dependencies B) There are only two columns in the entity C) Every non-primary key attribute is functionally dependent on the entire primary key D) A & C E) All of the above

A is part of the requirement for 3NF. B is a situation under which a relation is always in 3NF. C is a requirement for 2NF, which is required for 3NF. D is incomplete, trick answer. E is the true answer.

Each of these students are given a Student ID, name, address, email, and phone number. Which one of these attributes would be best used as a Primary Key? A) Student ID B) Name C) Address D) Email E) Phone number

A is the correct answer.

What is not an objective in determining data type? A) Always have a default value for the data type B) Support all data manipulations desired on the field C) Represent all possible values of the field D) Minimize storage space E) Improve data integrity for the field

A is the correct answer. B-E are all the objectives for choosing a data type and are all ideas that are meant for the datatype to have. They are not necessary but are there to help create a well balanced datatype.

What is referential integrity? A) The concept of a relation being completely normalized. B) The value of an attribute in one relation depends on the value of the same attribute in another relation. C) All foreign key attributes are multivalued. D) The idea that all entities have foreign keys referring to attributes in other entities.

B is correct. Referential integrity refers to an attribute in one relation that relies on the value of an attribute in another relation and has a value that is consistent with that

What is the difference between Second normal form (2NF) and Third normal form (2NF)? A) Second normal form requires that there be no secondary keys. B) Second normal form requires that every nonprimary key attribute be functionally dependent on the whole primary key. C) Third normal form requires that there be no functional (transitive) dependencies between two (or more) nonprimary key attributes. D) Third normal form requires that every nonprimary key attribute be functionally dependent on the whole primary key. E) Third normal form requires that all redundancy based on functional dependency be removed, although other types of redundancy may still exist.

A- secondary keys are not involved here B- this is the requirement of second normal form, which is also required by third normal form C is the correct answer - this is the requirement of third normal form, which is not required by second normal form D- this is a requirement of both second and third normal form E- this is the requirement of Boyce-Codd normal form

Which of the following is most associated with a unary 1:N relationship? A) Composite primary key B) Foreign Key C) Recursive Foreign Key D) Primary Relationship Key E) Transitive dependency

A: A composite primary key is used in M:N relationships to link two entities in a third, separate, entity B: A foreign key is a common idea across all relationships, where any primary key is used as a nonprimary attribute in another entity C: (Correct) A recursive foreign key is when a value references a primary key of the same entity, particularly seen in a unary 1:N relationship. The example given in the book is an Employee entity with "Emp_ID" and "Manager_ID" D: The primary key of a superclass in a supertype-subtype realationship E: A functional dependency between nonprimary key attributes, not strictly related to unary relationships

Which one is the best definition of normalization? A) A process for converting complex data structures into simple, stable data structures B) A process for converting simple data structures into complex data structures C) A relation that contains a minimum amount of redundancy and that allows users to insert, modify, and delete the rows without error or inconsistencies D) None of above

A: Correct: this is correct of normalization's definition. B: INCORRECT: Because, normalization's goal is to make complex data into simple data structures C: INCORRECT: That is definition of well-structured relation D: INCORRECT

Which of the following is not a key physical database design decision? A) Choosing the storage format for each attribute from the logical database model B) Grouping attributes from the logical database model into physical records C) Arranging related records in secondary memory so that individual records and groups of records can be stored, retrieved, and updated rapidly D) Combine normalized data requirements from all user interfaces into one consolidated database model E) Selecting media and structures for storing data to make access more efficient

Answer D is the second step in Logical Database Modeling and Design, not Physical Database Modeling and Design, making it the correct answer to this question.

A data model that does not contain repeating fields and that the data models leads to tables containing fields that are dependent on a whole primary key is in ____ normal form. A) 1NF B) 2NF C) 3NF D) BCNF

Answer is B. 2NF (Second Normal Form) is a normal form used in database normalization.

True or False: If a foreign key is null, it fails to satisfy referential integrity. A) True B) False C) A null value is invalid unless explicitly allowed in the database schema.

B is correct. Referential integrity states that the foreign key value must match a primary key value in another relation or the foreign key value must be null. Therefore, a value of null is still valid, and there is no need to explicitly allow for it.

What does a guard condition stop? A) It stops the transition diagram from depicting too many classes. B) It stops a transition from occurring if a certain condition is not met. C) It stops the transition diagram from having too many initial states. D) It stops a certain state from being in too many transition diagrams.

B is correct. Since a guard condition only lets a transition occur if the state has met a certain condition, it therefore stops a transition from occurring if a condition is not met. all other options are either nonsense or do not apply to the question.

If STUDENT and COURSE participate in a relationship, their relationship is a(n): A) Unary relationships B) Binary relationships C) Ternary relationships

B is correct because this is the most common type of relationship encountered in data.

Why should you examine your class diagram? A) Identify which classes are ready to go B) Identify which classes will need to undergo a complex series of state changes C) Fix the names of classes

B is correct.

We should create a state machine diagram when... A) We need to show how a particular scenario is executed over a set of classes. B) We are interested in understanding the dynamic aspects of a single class and how instances evolve over time. C) We need to understand how a single object behave with other classes on the system. D) We need to create a new class on the system.

b) CORRECT. That's when we need to create a state transition diagram.

I am looking to organize the physical file of my database so that I can quickly randomly retrieve on primary key and easily make modifications, and space is not an issue. Which family of file organization should I use? A) Sequential File Organizations B) Indexed File Organizations C) Hashed File Organizations

C is correct. In this case you should use a Hashed file organization because it allows you to easily make modifications and quick random retrievals. Indexed is a good middle ground with moderately fast speeds for everything and some maintenance of the indexes when making modifications. Sequential is poor if you want to make modifications. It is great for sequential retrieval but requires rewriting the file or reorganizing after modification.

Which of the following is not a type of file organization? A) Sequential File Organizations B) Index File Organizations C) Semi-sequential file organization D) Hashed file organization E) Summary of file organization

C is the correct answer.

Which of the following does not fit with a "top-down" approach to data modeling? A) Conducting an interview to determine the source of the data and who is allowed to access it. B) Inquiring about the characteristics of business subjects / objects. C) Examining reports to determine attributes of business subjects / objects. D) Examining business practices for special circumstances.

C) Examining reports to determine attributes of business subjects / objects. Top-down is looking at the whole system, whereas bottom-up is looking at specifics.

What is not true of indexing? A) Extra space is required to store the indexes B) Extra time is required to access and maintain indexes C) Indexes are part of the data in the database D) You can build multiple index structures on the same data file

C) Indexes are part of the data in the database Indexes are separate from the data. In the example given in the text, indexes are similar to a library catalog of books. Indexes are not the books, they just reference the books.

What is true about a guard condition? A) It represents the transition between states B) It changes a value that describes an object C) It is a boolean expression that includes attribute values D) It is shown as a small filled-in circle

C) It is a boolean expression that includes attribute values

Suppose you have a table detailing information about guests who have registered to participate in some event on RIT's campus. The fields include registration number (unique identifier given to all registrants upon payment), name, VIP status, group number (unique identifier given to groups of guests who have indicated they are attending the event together), meal preference, and T-shirt size. Which of the following are valid functional dependencies for this situation? A) Registration number --> T-shirt size B) Name --> VIP status C) Registration number, name --> meal preference D) A and B could both be considered correct E) A and C could both be considered correct

E is the correct option because it identifies both valid functional dependencies for this case.

Design Specification for interfaces and dialogue designs includes these section(s). A) Narrative Overview B) Sample Design C) Testing and Usability Assessment D) Dialogue Sequence E) All of the Above

E) All of the Above

What are some examples or concepts of controlling data integrity? A) Default Value: A value a field will assume unless an explicit value is entered for that field. B) Range Control: limits the range of values that can be entered into the field. Both numeric and alphanumeric data. C) Referential Integrity: An integrity constraint specifying that the value or existence of an attribute in one relation depends on the value or existence of the same attribute in another relation. D) Null Value: a special field value, distinct from zero, blank, or any other value, that indicates that the value for the field is missing or otherwise unknown. E) All of the above

E) All of the above

When naming and defining a relationship, what guidelines should be followed A) A name that is a verb phrase and in the present tense B) A definition clearly explaining what action is being taken and why it is important C) Explaining any restrictions on participation in the relationship D) Explaining whether an entity instance involved in a relationship instance can transfer participation to another relationship instance E) All of the above

E) All of the above

Which of the following is true about state changes? A) An event occurs once a state begins to transition to another state. B) An object enters the system by transitioning out of the initial state. C) An object must transition through all states before reaching the final state. D) A change in states can be initiated by event or a property of the state (e.g. a period of time passes). E) A change between states is always initiated by an event.

E) True, by definition transitions are triggered by events, and the events are used as labels for the transitions. However, an event can take many forms (basically any verb) and there is no requirement for there to be an outside actor, so for example a period of time passing would be an event as well. A "property of a state" has no bearing on state changes.

Which of the following is NOT a typical requirements determination question used for data modeling? A) What are the subjects/objects of the business? B) What characteristics describe each object? C) Why do you need to model these data? D) Over what period of time are you interested in these data? E) Are all instances of each object the same?

The correct answer is answer C. There are many benefits to modeling data, such as creating a more concise and understandable concept or diagram on how data is used in a business. This is not a question that you would ask during a requirements determination session.

1NF, 2NF, 3NF

The data depends on the key (1NF), the whole key (2NF), and nothing but the key (3NF)

A storage format that each attribute from the logical database model is stored as in the database is called a data type. A) True B) False

True

What is the first perspective when you do data modeling from a combination of perspective? A) Top-down approach B) Down-top approach C) Business approach D) None of above

The correct answer is A) Top-down approach because according to text, "this perspective derives the business rules for a data model from an intimate understanding of the nature of the business, rather than from any specific information requirements in computer displays, reports, or business forms" (261).

True of False: A recursive foreign key references the primary key values of the same relation. A) True B) False

True. A recursive foreign key is a foreign key in a relation that references the primary key values of that same relation. We can represent the relationship as follows: EMPLOYEE(Emp_ID, Name, Birthdate, Manager_ID) In this relation, Manager_ID is a recursive foreign key that takes its values from the same set of worker identification numbers as Emp_ID.

Which of the following is NOT a UML keyword? A) Overlapping B) Underlapping C) Complete D) Incomplete E) Overlapping

Underlapping is a made up term. The others are UML Keywords

What is true about data flows and data modeling? A) Data entities corresponds to sources/sinks in a Data flow diagram. B) All data flows will be represented as relationships in a E-R Diagram. C) Data stores in a process model must relate to data entities in the data model. D) Data flows and relationships should be named with nouns.

(FALSE) A, B - The only thing in common with data entities and sources/sinks and data flows and relationships are some of their notations. (TRUE) C - Each data store in a process model must relate to business objects (data entities) represented in the data model. (FALSE) D - Data flows are named using nouns, however, relationship names are verb phrases, usually in the present tense

Which of the following is not an important part of naming entity types? A) An entity type name should indicate if a value for the entity name may change. B) An entity type name is a singular noun. C) An entity type name should be concise. D) An entity type name should be descriptive and specific to the organization. E) An entity type name should include a statement of what the unique characteristics are for each instance of the entity type.

A) Is the correct answer as it is an important part of naming attributes, not a part of naming entities.

A state diagram specifically describes the behavior of a single object in response to a series of events in a system. A) True B) False

A) True

Which of the following is a file organization in which rows are stored either sequentially or non-sequentially, and an index is created that allows software to locate individual rows? A) Sequential file organization B) Indexed file organization C) Hashed file organization D) None of the above

B is the correct answer because an Indexed file organization is a file organization in which rows are stored either sequentially or non-sequentially. (pg. 340) A was wrong because a Sequential file organization is a file organization in which rows in a file are stored in sequence according to a primary key value. (pg. 340) C was wrong because a Hashed file organization is a file organization in which the address of each row is determined using an algorithm. (Pg.342)

Which of the following is NOT a guideline for attribute naming? A) An attribute name should be unique. B) An attribute definition explains what action is being taken and possibly why it is important. C) An attribute name is a noun D) To make an attribute name unique and for clarity, each attribute name should follow a standard format.

B is the correct answer because this is a guideline for a relationship definition.

What is the requirement for 3rd Normal Form? A) A relation is in third normal form (3NF) if meets all lower requirements and each row is unique. B) A relation is in third normal form (3NF) if meets all lower requirements and there are no functional dependencies between two or more nonprimary key attributes. C) A relation is in third normal form (3NF) if meets all lower requirements and every nonprimary key attribute is functionally dependent on the whole primary key. D) A relation is in third normal form (3NF) if meets all lower requirements and the sequence of columns can be interchanged without changing the meaning or use of the relation.

B is the correct answer.

A repeating group is a group of at least three multivalued attributes that are logically related. A) True B) False

B) False

If an entity instance may or may not belong to a subclass, and must belong to only one subclass, what business rules apply to this entity? A) Partial Specialization and Overlap B) Partial Specialization and Disjoint C) Total Specialization and Overlap D) Total Specialization and Disjoint

B) Partial Specialization and Disjoint The partial specialization rule specifies that an entity instance of the supertype does not have to belong to any subtype. The total specialization rule specifies that each entity instance of the supertype must be a member of some subtype. The overlap rule specifies that an entity instance can be a member of two or more subtypes. The disjoint rule specifies that an entity instance can only be a member of one subtype.

___ is a set of values that describes an object at a specific point in time, and it represents a point in an object's life which it satisfies some condition, performs some action, or waits for something to happen. A) Transition B) State C) Event D) None of the above

B) State

A transition is NOT... A) Indicates that an object in the first state will enter the second state B) Is triggered by the occurrence of the event labeling the transition C) is a noteworthy occurrence that triggers a change in state D) is shown as a solid arrow from one state to another, labeled by the event name

C) is a noteworthy occurrence that triggers a change in state

Which of the following is not proper notation for showing relationships? A) One to many B) One to one C) One and only one D) One to two E) Zero or One

D is the answer. One to two can be expressed simply as one to many

Which definition best fits that of a domain? A) A descriptor for the type of relationship two entities may have. B) The rule that governs the validity of data manipulation. C) The conceptual organizational unit that entities and their attributes exist in. D) A set of all data types and ranges of values that attributes may assume.

D is the correct answer.

Partial participation is different from total participation because... A) Only part of the entity participates in the relationship B) Partial participation means an entity occurrence can only exist if it is part of the relationship C) Only strong entities can have total participation D) An entity occurrence can exist in the model but is optional and does not have to be in the stated relationship E) In partial participation, the two entities share in a one to many relationship

D) An entity occurrence can exist in the model but is optional and does not have to be in the stated relationship

Given these options, choose your answer according to what is right about Normalization: I. Functional dependency is a term used to identify when nonprimary key attributes depend on each other. II. A relation is in second normal form (2NF) if no nonprimary key attribute is functionally dependent on part, but not all, of the primary key. III. Normalization is a process for converting complex data structures into simple, stable data structures. IV. If a relation is in third normal form (3NF) it means that it is mandatorily in second normal form (2NF). V. A relation can be in second normal form (2NF) but not in the first normal form (1NF). A) I, II, III are correct. B) I, III, IV are correct. C) II, III, IV are correct. D) III, IV are correct. E) All alternatives are correct.

I. Transitive dependency is a term used to identify when nonprimary key attributes depend on each other. II. A relation is in second normal form (2NF) if no nonprimary key attribute is functionally dependent on part, but not all, of the primary key. III. Normalization is a process for converting complex data structures into simple, stable data structures. IV. If a relation is in third normal form (3NF) it means that it is mandatorily in second normal form (2NF). V. A relation can't be in second normal form (2NF) if it's not in the first normal form (1NF). C is Correct: II, III, IV.