Podcast
Questions and Answers
At least two professors must be qualified to teach each ______.
At least two professors must be qualified to teach each ______.
course
Each professor must be qualified to teach at least one ______.
Each professor must be qualified to teach at least one ______.
course
Figure 2-15a and 2-15b Multivalued attributes can be represented as ______.
Figure 2-15a and 2-15b Multivalued attributes can be represented as ______.
relationships
Figure 2-11a A ______ relationship with an attribute.
Figure 2-11a A ______ relationship with an attribute.
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Figure 2-13c An associative entity – bill of materials ______.
Figure 2-13c An associative entity – bill of materials ______.
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Figure 2-18 Cardinality constraints in a ternary ______.
Figure 2-18 Cardinality constraints in a ternary ______.
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A composite attribute is broken into ______ parts
A composite attribute is broken into ______ parts
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A multivalued attribute may take on more than one value for a given entity instance, while a derived attribute can be calculated from related attribute values and is not physically stored in the database. (______/False)
A multivalued attribute may take on more than one value for a given entity instance, while a derived attribute can be calculated from related attribute values and is not physically stored in the database. (______/False)
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In a binary relationship, ______ entities are related to each other
In a binary relationship, ______ entities are related to each other
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The degree of relationships refers to how many entities are related to each other. It can be one entity related to another entity of the same type, or entities of ______ different types related to each other
The degree of relationships refers to how many entities are related to each other. It can be one entity related to another entity of the same type, or entities of ______ different types related to each other
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A unary relationship involves ______ entity
A unary relationship involves ______ entity
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Cardinality constraints define the number of instances in a relationship. In a mandatory cardinality, a patient history is recorded for ______ patient
Cardinality constraints define the number of instances in a relationship. In a mandatory cardinality, a patient history is recorded for ______ patient
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In a binary relationship, the ______ specifies how many of each entity type is allowed
In a binary relationship, the ______ specifies how many of each entity type is allowed
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A good business rule focuses on defining the interactions between ______
A good business rule focuses on defining the interactions between ______
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The degree of relationships specifies the number of ______ types involved
The degree of relationships specifies the number of ______ types involved
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An entity that is also a relationship is a ______ entity
An entity that is also a relationship is a ______ entity
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Unary relationships involve ______ entity type
Unary relationships involve ______ entity type
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Study Notes
Educational Qualification Requirements
- At least two professors needed for each subject area.
- Each professor must be qualified to teach a minimum of one subject.
Database Design Concepts
- Multivalued attributes can be represented in specific formats for efficient data handling.
- Associative entities help manage complex relationships, such as a "bill of materials."
- Cardinality constraints illustrate how entities interact within ternary relationships.
Attributes in Databases
- Composite attributes can be divided into finer parts for better organization.
- A multivalued attribute allows multiple values for a single entity instance.
- Derived attributes are calculated from related values, and not stored physically in the database.
Types of Relationships
- In a binary relationship, two entities are interrelated.
- Relationships can involve one type of entity or multiple types, reflecting the degree of the relationship.
- Unary relationships involve a single entity type, allowing self-referencing.
Cardinality and Business Rules
- Cardinality constraints dictate the number of instances in a relationship (e.g., mandatory histories for patients).
- In a binary relationship, specific rules define the allowable instances for each entity type.
- Effective business rules clarify the interactions between different entities and are crucial for database integrity.
- The degree of relationships quantifies the number of entity types engaged in the interaction.
Unique Concepts
- Entities that also function as relationships are known as associative entities.
- Unary relationships focus on a single entity type, enhancing the complexity of data structuring.
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Description
Learn about composite attributes, which break down the address into component parts. Understand multivalued attributes that can have more than one value for a given entity and derived attributes that are calculated from related attribute values. Explore examples like an entity with multivalued attribute (Skill) and derived attribute (Years Employed).
