3.1. Given the ER model above, which of the following statements is correct? 3.2. a. A movie can have as many lead actors as there are actors in the movie. b. PRODUCER is an existence-dependent entity type. c. A director of a movie can also act in the same movie. d. A movie can have multiple actors, producers, and directors. In the movie ER model above, we focus on the binary relationship "PRODUCES". Suppose we add an attribute type that indicates the time that each producer spent on producing each movie called "WORKING HOURS". Which of the following scenarios is possible? a. We can migrate the attribute type "WORKING HOURS" to the "MOVIE" entity type. b. We can migrate the attribute type "WORKING HOURS" to the "PRODUCER" entity type. c. We can migrate the attribute type "WORKING HOURS" to either one of the linked entity types. d. We can add the attribute type "WORKING HOURS" to the relationship type PRODUCES. Which statement is correct? 3.3. a. In the case a ternary relationship type is represented as three binary relationship types, then semantics will get lost. b. A ternary relationship type can always be represented as three binary relationship types without loss of semantics. c. Three binary relationship types between three entity types can always be replaced by one ternary relationship type between the three participating entity types. d. A ternary relationship type cannot have attribute types. Which statements are correct? a. A weak entity type can only have one attribute type. b. A weak entity type is always existence-dependent. c. An existence-dependent entity type is always a weak entity type. d. An existence-dependent entity type always participates in a 1:1 relationship type. 3.4. 3.1. Given the ER model above, which of the following statements is correct? 3.2. a. A movie can have as many lead actors as there are actors in the movie. b. PRODUCER is an existence-dependent entity type. c. A director of a movie can also act in the same movie. d. A movie can have multiple actors, producers, and directors. In the movie ER model above, we focus on the binary relationship "PRODUCES". Suppose we add an attribute type that indicates the time that each producer spent on producing each movie called "WORKING HOURS". Which of the following scenarios is possible? a. We can migrate the attribute type "WORKING HOURS" to the "MOVIE" entity type. b. We can migrate the attribute type "WORKING HOURS" to the "PRODUCER" entity type. c. We can migrate the attribute type "WORKING HOURS" to either one of the linked entity types. d. We can add the attribute type "WORKING HOURS" to the relationship type PRODUCES. Which statement is correct? 3.3. a. In the case a ternary relationship type is represented as three binary relationship types, then semantics will get lost. b. A ternary relationship type can always be represented as three binary relationship types without loss of semantics. c. Three binary relationship types between three entity types can always be replaced by one ternary relationship type between the three participating entity types. d. A ternary relationship type cannot have attribute types. Which statements are correct? a. A weak entity type can only have one attribute type. b. A weak entity type is always existence-dependent. c. An existence-dependent entity type is always a weak entity type. d. An existence-dependent entity type always participates in a 1:1 relationship type. 3.4
