Answer: True Page: 270 LOD: Easy
Answer: False Page: 270 LOD: Medium
Rationale: Data modeling is a technique for organizing and documenting a system’s data.
Answer: True Page: 270 LOD: Easy
Answer: False Page: 271 LOD: Medium Rationale: An entity is a class of persons, places, objects, events or concepts about which we need to capture and store data.
Answer: True Page: 272 LOD: Easy
Answer: False Page: 272 LOD: Easy
Rationale: An entity instance is a single occurrence of an entity.
Answer: True Page: 272 LOD: Easy
Answer: True Page: 272 LOD: Easy
Answer: False Page: 272 LOD: Medium
Rationale: A compound attribute is one that actually consists of other attributes that are logically grouped together.
Answer: True Page: 272 LOD: Easy
Answer: True Page: 272 LOD: Easy
Answer: True Page: 273 LOD: Easy
Answer: False Page: 273 LOD: Medium
Rationale: A key is an attribute, or group of attributes, that assumes a unique value for each entity instance. It is sometimes called an identifier.
Answer: True Page: 273 LOD: Easy
Answer: True Page: 273 LOD: Easy
Answer: False Page: 274 LOD: Medium
Rationale: A candidate key may be a single attribute or a concatenated key.
Answer: True Page: 274 LOD: Easy
Answer: True Page: 274 LOD: Easy
Answer: True Page: 272 LOD: Medium
Answer: True Page: 274 LOD: Easy
Answer: False Page: 274 LOD: Medium
Rationale: A subsetting criteria is an attribute or concatenated attribute whose finite values divide all entity instances into useful subsets.
Answer: True Page: 275 LOD: Easy
Answer: False Page: 275 LOD: Hard
Rationale: A relationship may represent an event that links the entities or merely a logical affinity that exists between the entities.
Answer: False Page: 275 LOD: Medium
Rationale: Relationships are bi-directional.