What is Database Management System (DBMS)?, What is the Purpose of Database System?, Examples of Database Management System

What is Database Management System (DBMS)?, What is the Purpose of Database System?, Examples of Database Management System


What is Database Management System (DBMS)?
Database management system is a Collection of interrelated data
And Set of programs to access the data .
 DBMS contains information about a particular enterprise
 DBMS provides an environment that is both convenient and
efficient to use.
 Database Applications:
 Banking: all transactions
 Airlines: reservations, schedules
 Universities: registration, grades
 Sales: customers, products, purchases
 Manufacturing: production, inventory, orders, supply chain
 Human resources: employee records, salaries, tax deductions


What is the Purpose of Database System?
Using Database solves this problems

• Data redundancy and inconsistency
• Multiple file formats, duplication of information in different files
• Difficulty in accessing data
• Need to write a new program to carry out each new task
• Data isolation — multiple files and formats
• Integrity problems
• Integrity constraints (e.g. account balance > 0) become part
• of program code
• Hard to add new constraints or change existing ones
• Atomicity of updates
• Failures may leave database in an inconsistent state with partial
• updates carried out
• E.g. transfer of funds from one account to another should either
• complete or not happen at all
• Concurrent access by multiple users
• Concurrent accessed needed for performance
• Uncontrolled concurrent accesses can lead to inconsistencies
• – E.g. two people reading a balance and updating it at the same
• time
• Security problems