2 Database Systems versus File Systems In the early days, database applications were built on top of file systems Drawbacks of using file systems to store data: 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 Database System Concepts 1.5 OSilberschatz. Korth and SudarshanDatabase System Concepts 1.5 ©Silberschatz, Korth and Sudarshan 2 Database Systems versus File Systems In the early days, database applications were built on top of file systems Drawbacks of using file systems to store data: 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