Explain the component modules of DBMS & their interactions with diagram

Explain the component modules of DBMS & their interactions with diagram

Answer:-

In the Entity-Relationship (ER) model, attributes describe the properties or characteristics of entities or relationships. There are several types of attributes based on their nature and structure.

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Types of Attributes in ER Model

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1. Simple (Atomic) Attribute

• Cannot be divided further.
• Represent a single value.
• Example: Name, Age, Salary

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2. Composite Attribute

• Can be divided into smaller sub-parts.
• Sub-parts are meaningful on their own.
• Example:
  FullName → can be split into FirstName, LastName
Address → can be split into Street, City, Zip

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3. Derived Attribute

• Not stored in the database directly.
• Can be calculated from other attributes.
• Example:
  Age can be derived from DateOfBirth
TotalPrice from Quantity × UnitPrice

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4. Multi-Valued Attribute

• Can have multiple values for a single entity.
• Usually shown as double ovals in ER diagrams.
• Example:
  A person may have multiple PhoneNumbers or EmailAddresses.

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5. Key Attribute

• Used to uniquely identify an entity.
• It is part of the primary key.
• Example:
  RollNo for a student, EmployeeID for an employee

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6. Single-Valued Attribute

• Holds only one value for a given entity.
• Example: DateOfBirth, Gender

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✅ Summary Table

Attribute Type	Description	Example
Simple (Atomic)	Cannot be divided	Name, Age
Composite	Can be divided into sub-parts	Address → City, Zip
Derived	Calculated from other attributes	Age from DateOfBirth
Multi-Valued	Has multiple values for one entity	PhoneNumbers
Key	Uniquely identifies an entity	EmployeeID
Single-Valued	Holds only one value per entity	Gender