Question 1: Please specify which concept the following symbols refer to in a digram of an entityrelationship model: (A) Rectangle (B) Oval (C) Diamond Question 2: In an E-R model of a university, is it better to set the "grade" of students an attribute of Student entity type, Class entity type, or Enroll relationship type? Question 3: What is an Entity set? Question 4: An entity set should be well defined. What does this mean? Question 5: In a good logical model, which one is permanent? Entity type or entity set? Question 6: In an E-R model, is it possible for entity sets to intersect? Question 7: The range of valid values that an attribute can take is referred to as Question 8: Which one of the following is correct for an E-R model? (A) Attributes cannot take null values. (B) Non-composite supperkeys cannot take null values (C) Domains can include null values. Question 9: In a digram of an E-R model, a double oval indicates: (A) An attribute that can take no null values. (B) An attribute with an empty domain. (C) A multi-valued attribute. (D) An entity set that has at least one attribute. Question 10: In a small college, the set of \{firstname, lastname\} identifies the students uniquely. Is the set { firstname, lastname } a superkey? Question 11: which one is correct regarding an entity set of an E-R model? (A) The number of superkeys >= The number of candidate keys >= The number of primary keys (B) The number of candidate keys >= The number of superkeys >= The number of primary keys (C) The number of primary keys >= The number of superkeys >= The number of candidate keys Question 12: A is a superkey that no subset of its attributes is itself a superkey. Question 13: Sometime a secondary key is selected for an entity set in an E-R model. Which one is correct regarding a secondary key: (A) A secondary key uniquely identifies the entity instances of the entity set and must be a superkey. (B) A secondary key does not need to be a superkey but must uniquely identify the entity instances of the entity set. (C) A secondary key is used for indexing the entity instances and must be a superkey. (D) A secondary key is used for indexing the entity instances and does not need to be a superkey. Question 14: In Figure 3.13 of the textbook, what is the degree of following relationships: (A) HasMajor (B) Offers (C) Chairs (D) Employ Question 15: What is a recursive relationship? Question 16: Consider the entity sets E1,E2,,En. R is an n degree relationship between these entity Question 17: In Figure 3.10 of the textbook, what is the cardinality of the following relationship: (A) Department-Faculty Question 18: From Figure 3.9 of the textbook what is the minimum number of classes that a faculty member should teach? Question 19: Show the cardinality and participation constraint for a Mother-Child relationship, using (min,max) notation. Question 20: Y is an entity set that is existence dependent on X. Which one is not correct? (A) For Y we don't need to specify a primary key (B) Y is a child entity and X is a parent entity (C) Each instances of X must be corresponding to an instance of Y. (D) X is the strong entity set and Y is the weak entity set