DBMG Chap.2

63) When choosing an identifier, choose one that will not change its value often.

Answer: TRUE

65) Data, rather than processes, are the most complex aspects of many modern information systems.

Answer: TRUE

61) A single occurrence of an entity is called an entity instance.

Answer: TRUE

80) Participation in a relationship may be optional or mandatory.

Answer: TRUE

15) A(n) ________ is the relationship between a weak entity type and its owner. A) member chain B) identifying relationship C) jump path D) chain link

B) identifying relationship

3) A fact is an association between two or more: A) words. B) terms. C) facts. D) nuggets.

Answer: B

30) In the figure below, which attribute is derived? A) Years_Employed B) Employee_ID C) Skill D) Address

A) Years_Employed

17) A property or characteristic of an entity type that is of interest to the organization is called a(n): A) attribute. B) coexisting entity. C) relationship. D) cross-function.

A) attribute.

11) Customers, cars, and parts are examples of: A) entities. B) attributes. C) cardinals. D) relationships.

A) entities.

6) In an E-R diagram, there are/is ________ business rule(s) for every relationship. A) two B) three C) one D) zero

A) two

67) The purpose of data modeling is to document business rules about processes.

Answer: FALSE

68) In an E-R diagram, strong entities are represented by double-walled rectangles.

Answer: FALSE

70) Data names do not have to be unique.

Answer: FALSE

54) A business rule should be internally consistent.

Answer: TRUE

71) The relationship between a weak entity type and its owner is an identifying relationship.

Answer: TRUE

77) An attribute whose values can be calculated from related attribute values is called a derived attribute.

Answer: TRUE

62) In the figure below, Name would be an ideal identifier.

Answer: FALSE

64) Most systems developers believe that data modeling is the least important part of the systems development process.

Answer: FALSE

53) While business rules are not redundant, a business rule can refer to another business rule.

Answer: TRUE

58) A fact is an association between two or more terms.

Answer: TRUE

52) A business rule is a statement of how a policy is enforced or conducted.

Answer: FALSE

4) Data modeling may be the most important part of the systems development process because: A) data characteristics are important in the design of programs and other systems components. B) the data in a system are generally less complex than processes and play a central role in development. C) data are less stable than processes. D) it is the easiest.

A) data characteristics are important in the design of programs and other systems components.

32) The total quiz points for a student for an entire semester is a(n) ________ attribute. A) derived B) mixed C) stored D) addressed

A) derived

57) An example of a term would be the following sentence: "A student registers for a course."

Answer: FALSE

72) An entity type on which a strong entity is dependent is called a covariant entity.

Answer: FALSE

74) The name used for an entity type should never be the same in other E-R diagrams on which the entity appears.

Answer: FALSE

1) The logical representation of an organization's data is called a(n): A) database model. B) entity-relationship model. C) relationship systems design. D) database entity diagram.

B) entity-relationship model.

9) Which of the following is NOT a characteristic of a good business rule? A) Declarative B) Atomic C) Inconsistent D) Expressible

C) Inconsistent

29) In the figure below, which attribute is multivalued? A) Years_Employed B) Employee_ID C) Skill D) Address

C) Skill

12) Which of the following is an entity that exists independently of other entity types? A) Codependent B) Weak C) Strong D) Variant

C) Strong

37) A relationship where the minimum and maximum cardinality are both one is a(n) ________ relationship. A) optional B) unidirectional C) mandatory link D) mandatory one

D) mandatory one

28) The following figure shows an example of: A) a composite attribute. B) a relational attribute. C) a derived attribute. D) a multivalued attribute.

A) a composite attribute.

2) A good data definition will describe all of the characteristics of a data object EXCEPT: A) subtleties. B) examples. C) who determines the value of the data. D) who can delete the data.

Answer: D

49) The intent of a business rule is to break down business structure.

Answer: FALSE

51) When systems are automatically generated and maintained, quality is diminished.

Answer: FALSE

55) Business rules are formulated from a collection of business ramblings.

Answer: FALSE

76) A simple attribute can be broken down into smaller pieces.

Answer: FALSE

81) A ternary relationship is equivalent to three binary relationships.

Answer: FALSE

82) The degree of a relationship is the number of attributes that are associated with it.

Answer: FALSE

84) The relationship among the instances of three entity types is called a unary relationship.

Answer: FALSE

73) An entity type name should always be a singular noun.

Answer: TRUE

40) For the relationship represented in the figure below, which of the following is true? A) An employee can work in more than one department but does not have to work for any department. B) A department must have at least one employee. C) A department can have more than one employee. D) An employee has to work for more than one department.

C) A department can have more than one employee.

20) An attribute of an entity that must have a value for each entity instance is a(n): A) optional attribute. B) composite attribute. C) required attribute. D) fuzzy attribute

C) required attribute.

8) A ________ defines or constrains some aspect of the business. A) business constraint B) business structure C) business control D) business rule

D) business rule

31) An attribute that can be calculated from related attribute values is called a ________ attribute. A) simple B) composite C) multivalued D) derived

D) derived

39) In the figure shown below, which of the following is true? A) A person can marry at most one person. B) A person has to be married. C) A person can marry more than one person, but that person can only be married to one person. D) A person can marry more than one person.

A) A person can marry at most one person.

43) In the following diagram, which answer is true? A) Each employee can supervise one employee, no employees or many employees. B) Each employee can manage many departments. C) Each employee works in more than one department. D) Each employee was fired.

A) Each employee can supervise one employee, no employees or many employees.

41) In the following diagram, which of the answers below is true? A) Each patient has one or more patient histories. B) Each patient has one and only one visit. C) Each patient history belongs to zero and one patient. D) Each patient history belongs to many patients.

A) Each patient has one or more patient histories.

42) In the figure shown below, which of the following business rules would apply? A) Each vendor can supply many parts to any number of warehouses, but need not supply any parts. B) Each part must be supplied by exactly one vendor to any number of warehouses. C) Each warehouse can be supplied with any number of parts from more than one vendor, and each warehouse could be supplied with no parts. D) VENDOR is not allowed.

A) Each vendor can supply many parts to any number of warehouses, but need not supply any parts.

35) An entity that associates the instances of one or more entity types and contains attributes specific to the relationships is called a(n): A) associative entity. B) build entity. C) gateway entity. D) smush entity

A) associative entity.

19) A person's name, birthday, and social security number are all examples of: A) attributes. B) entities. C) relationships. D) descriptors.

A) attributes.

7) Business policies and rules govern all of the following EXCEPT: A) managing employees. B) creating data. C) updating data. D) removing data.

A) managing employees.

5) The most common types of entities are: A) strong entities. B) weak entities. C) associative entities. D) smush entities.

A) strong entities.

27) A simultaneous relationship among the instances of three entity types is called a ________ relationship. A) ternary B) tertiary C) primary D) binary

A) ternary

38) A mutually exclusive relationship is one in which: A) an entity instance can participate in many different relationships. B) an entity instance can participate in only one of several alternative relationships. C) an entity instance cannot participate in a relationship with another entity instance. D) an entity instance bridges other XML documents.

B) an entity instance can participate in only one of several alternative relationships.

36) A ________ specifies the number of instances of one entity that can be associated with each instance of another entity. A) degree B) cardinality constraint C) counter constraint D) limit

B) cardinality constraint

34) An attribute that uniquely identifies an entity and consists of a composite attribute is called a(n): A) composite attribute. B) composite identifier. C) identifying attribute. D) relationship identifier

B) composite identifier.

44) A student can attend five classes, each with a different professor. Each professor has 30 students. The relationship of students to professors is a ________ relationship. A) one-to-one B) many-to-many C) one-to-many D) strong

B) many-to-many

22) The number of entity types that participate in a Unary relationship is: A) zero. B) one. C) two. D) three.

B) one.

18) An attribute that must have a value for every entity (or relationship) instance is a(n): A) composite attribute. B) required attribute. C) optional attribute. D) multivalued attribute.

B) required attribute.

45) A value that indicates the date or time of a data value is called a: A) value stamp. B) time stamp. C) checkpoint. D) check counter

B) time stamp.

13) An entity type whose existence depends on another entity type is called a ________ entity. A) strong B) weak C) codependent D) variant

B) weak

23) The number of entity types that participate in a relationship is called the: A) number. B) identifying characteristic. C) degree. D) counter.

Answer: C

10) Which of the following is NOT a good characteristic of a data name? A) Relates to business characteristics B) Readable C) Repeatable D) Relates to a technical characteristic of the system

Answer: D

75) Some examples of attributes are: eye_color, weight, student_id, STUDENT.

Answer: FALSE

86) It is not permissible to associate attributes with relationships.

Answer: FALSE

87) A relationship instance is an association between entity instances where each relationship instance includes exactly one entity from each participating entity type.

Answer: FALSE

89) In the figure below, the name of the relationship follows the guidelines for naming a relationship.

Answer: FALSE

90) A cardinality constraint tells what kinds of properties are associated with an entity.

Answer: FALSE

91) The maximum criminality of a relationship is the maximum number of instances of entity B that may be associated with each instance of entity A.

Answer: FALSE

92) In the figure shown below, a person has to be married.

Answer: FALSE

94) A customer can order many items, and an item can be ordered by many customers is an example of a recursive relationship.

Answer: FALSE

46) The E-R model is used to construct a conceptual model.

Answer: TRUE

47) A business rule is a statement that defines or constrains some aspect of the business.

Answer: TRUE

48) One of the roles of a database analyst is to identify and understand rules that govern data.

Answer: TRUE

50) Enforcement of business rules can be automated through the use of software tools that can interpret the rules and enforce them.

Answer: TRUE

56) Data names should always relate to business characteristics.

Answer: TRUE

59) A good data definition is always accompanied by diagrams, such as the entity-relationship diagram.

Answer: TRUE

60) An entity is a person, place, object, event, or concept in the user environment about which the organization wishes to maintain data.

Answer: TRUE

66) Data modeling is about documenting rules and policies of an organization that govern data.

Answer: TRUE

69) In an E-R diagram, an associative entity is represented by a rounded rectangle.

Answer: TRUE

78) A multivalued attribute may take on more than one value for a particular entity instance.

Answer: TRUE

79) Relationships represent action being taken using a verb phrase.

Answer: TRUE

83) The relationship between the instances of two entity types is called a binary relationship.

Answer: TRUE

85) It is desirable that no two attributes across all entity types have the same name.

Answer: TRUE

88) One reason to use an associative entity is if the associative entity has one or more attributes in addition to the identifier.

Answer: TRUE

93) For the relationship represented in the figure below, a department can have more than one employee.

Answer: TRUE

95) A time stamp is a time value that is associated with a data value.

Answer: TRUE

26) In the following diagram, which is true? A) It depicts a ternary relationship. B) It depicts a many-to-many relationship. C) Item represents a column. D) BOM_STRUCTURE represents a row

B) It depicts a many-to-many relationship.

14) The following figure shows an example of: A) a one-to-many relationship. B) a strong entity and its associated weak entity. C) a co-dependent relationship. D) a double-walled relationship.

B) a strong entity and its associated weak entity.

33) Which of the following criteria should be considered when selecting an identifier? A) Choose an identifier that is not stable. B) Choose a null identifier. C) Choose an identifier that doesn't have large composite attributes. D) Choose the most complex identifier possible.

C) Choose an identifier that doesn't have large composite attributes.

25) In the following diagram, what type of relationship is depicted? A) Unary B) Binary C) Ternary D) Quad

C) Ternary

16) An entity type name should be all of the following EXCEPT: A) concise. B) specific to the organization. C) as short as possible. D) a singular noun.

C) as short as possible.

21) An attribute that can be broken down into smaller parts is called a(n) ________ attribute. A) associative B) simple C) composite D) complex

C) composite

24) A relationship between the instances of a single entity type is called a ________ relationship. A) ternary B) primary C) binary D) unary

D) unary