Week 1

1.3 File-Based Systems vs. Database Systems

Before databases, organisations stored data in flat files, separate files maintained by each department. This file-based approach led to serious problems:

Problem with File-Based Systems	Example from Nigeria
Data Redundancy: Same data stored in multiple files	A student's address stored in separate files for bursary, registry, and library all must be updated when they move
Data Inconsistency: Different files have different values for the same data	Student's phone number differs between the admissions file and the hostel file
Difficulty in Accessing Data: Each query requires custom programs	IT staff must write a new program every time management needs a new report
Data Isolation: Data scattered across many files in different formats	Combining data from HR (Excel) and Payroll (text files) requires manual effort
Integrity Problems: Hard to enforce rules across separate files	No automatic check that a staff payment doesn't exceed the budgeted amount
Security Problems: Difficult to control access at a fine-grained level	Either everyone can access the entire HR file or no one can
Concurrency Problems: Multiple users modifying files simultaneously causes corruption	Two clerks updating the same student record simultaneously corrupt the file