Database Fundamentals

Database Fundamentals

What is a Database?

• A collection of organized data that is stored in a way that allows for efficient retrieval and manipulation
• Provides a controlled environment for storing, updating, and retrieving data

Database Characteristics

• Persistence: Data is stored in a non-volatile memory, ensuring data survives system crashes or power failures
• Sharing: Multiple users can access and manipulate data simultaneously
• Data Independence: Data is separated from the applications that use it, allowing for changes to either without affecting the other

Database Management Systems (DBMS)

• Definition: A software system that allows for the definition, creation, maintenance, and manipulation of databases
• Functions:
  • Data definition: defining the structure of the database
  • Data manipulation: performing operations on the data
  • Data querying: retrieving specific data from the database
  • Data security: controlling access to the database
  • Data integrity: ensuring the accuracy and consistency of the data

Database Models

• Hierarchical Model: Organizes data into a tree-like structure, with each record having a single parent
• Network Model: Organizes data into a network of interconnected records, allowing for multiple parents
• Relational Model: Organizes data into tables with rows and columns, using keys to establish relationships between tables
• Object-Oriented Model: Organizes data into objects that contain both data and functions that operate on that data

Database Normalization

• Definition: The process of organizing the data in a database to minimize data redundancy and dependency
• Goals:
  • Eliminate data redundancy
  • Improve data integrity
  • Reduce data anomalies
• Normalization Rules:
  • First Normal Form (1NF): Each table cell must contain a single value
  • Second Normal Form (2NF): Each non-key attribute must depend on the entire primary key
  • Third Normal Form (3NF): If a table is in 2NF, and a non-key attribute depends on another non-key attribute, then it should be moved to a separate table

Database Security

• Threats:
  • Unauthorized access
  • Data tampering
  • Data loss or theft
• Security Measures:
  • Authentication: verifying the identity of users
  • Authorization: controlling access to database resources
  • Encryption: protecting data in transit and at rest
  • Access Control: limiting access to sensitive data and operations

Database Fundamentals

What is a Database?

• A collection of organized data that enables efficient retrieval and manipulation
• Provides a controlled environment for storing, updating, and retrieving data

Database Characteristics

• Persistence: Data is stored in non-volatile memory, ensuring data survival during system crashes or power failures
• Sharing: Multiple users can access and manipulate data simultaneously
• Data Independence: Data is separated from applications, allowing for changes to either without affecting the other

Database Management Systems (DBMS)

• Definition: Software that allows for defining, creating, maintaining, and manipulating databases
• Functions:
  • Defining the database structure
  • Performing operations on the data
  • Retrieving specific data from the database
  • Controlling access to the database
  • Ensuring data accuracy and consistency

Database Models

• Hierarchical Model: Organizes data into a tree-like structure, with each record having a single parent
• Network Model: Organizes data into a network of interconnected records, allowing for multiple parents
• Relational Model: Organizes data into tables with rows and columns, using keys to establish relationships between tables
• Object-Oriented Model: Organizes data into objects that contain both data and functions

Database Normalization

• Definition: The process of organizing data to minimize redundancy and dependency
• Goals:
  • Eliminate data redundancy
  • Improve data integrity
  • Reduce data anomalies
• Normalization Rules:
  • First Normal Form (1NF): Each table cell contains a single value
  • Second Normal Form (2NF): Each non-key attribute depends on the entire primary key
  • Third Normal Form (3NF): Non-key attribute depends on another non-key attribute, then it's moved to a separate table

Database Security

• Threats:
  • Unauthorized access
  • Data tampering
  • Data loss or theft
• Security Measures:
  • Authentication: verifying user identities
  • Authorization: controlling access to database resources
  • Encryption: protecting data in transit and at rest
  • Access Control: limiting access to sensitive data and operations

This quiz covers the basics of databases, including their definition, characteristics, and features that allow for efficient data storage and retrieval.