ch2 DB(Lecture 3) Flashcards
(21 cards)
What is a database?
Collection of related data
A database is designed to meet the information needs of an organization.
What is data?
Known facts that can be recorded and have an implicit meaning.
What is a Database Management System (DBMS)?
A collection of programs that enables users to create and maintain a database.
What does metadata refer to?
Data that describes the properties and context of user data.
List some examples of database applications.
- Purchases from the supermarket
- Purchases using your credit card
- Booking a holiday at the travel agents
- Using the local library
- Taking out insurance
- Renting a video
- Using the Internet
- Studying at university
What are the major components of the DBMS environment?
Personnel involved, database applications, and DBMS.
What are the disadvantages of file processing systems?
- Program-Data Dependence
- Data Redundancy
- Limited Data Sharing
- Lengthy Development Times
- Excessive Program Maintenance
- Inconsistency
What is the main advantage of the database approach compared to file processing?
A single repository of data is maintained that is defined once and accessed by various users.
What are the advantages of the database approach?
- Data Sharing
- Data Independence
- Controlled Redundancy
- Better Data Integrity
What are the typical functions of a DBMS?
- Defining a database
- Constructing the database
- Manipulating a database
- Sharing a database
- Protecting the database
Who are the actors on the scene in the database environment?
- Database administrators
- Database designers
- End-users
- System analysts
- Application programmers
Define the role of a database administrator.
Responsible for authorizing access to the database, coordinating and monitoring its use.
What is the role of database designers?
Define the content, structure, constraints, and functions or transactions against the database.
Fill in the blank: A _______ is responsible for determining the requirements of end users and developing specifications.
System analyst
What is concurrency control in a DBMS?
Guarantees that each transaction is correctly executed or aborted.
What is the purpose of the recovery subsystem in a DBMS?
Ensures each completed transaction has its effect permanently recorded in the database.
What are the typical categories of end-users?
- Casual
- Naïve or Parametric
- Sophisticated
True or False: A DBMS allows multiple users to access the database simultaneously.
True
What is the significance of a system catalog in a database?
Provides description of data to enable program–data independence.
What does the term ‘controlled redundancy’ mean in the context of DBMS?
Minimizes duplication of data across different systems.
What is the primary function of the DBMS regarding data protection?
Protecting the database against unauthorized access and hardware/software malfunctions.
