DBMS vs. File Processing
Lecture 1 · why we moved from scattered files to a managed database. Learn the six drawbacks — they're the classic “why DBMS?” question.
File processing — the 6 drawbacks
RI·IACSRedundancy · Isolation · Integrity · Atomicity · Concurrency · Security.
| Drawback | What goes wrong |
|---|---|
| Data redundancy & inconsistency | Same fact stored in many files → two different addresses for one person. |
| Data isolation | Data scattered across files/formats → hard to write programs that pull related data. |
| Integrity problems | Constraints (e.g. “salary > 0”) are buried in application code, not enforced centrally. |
| Atomicity problems | A crash mid-operation leaves half-done work — money debited but never credited. |
| Concurrent-access anomalies | Two users at once → inconsistent results (both book the last seat). |
| Security issues | Hard to give differentiated access (HR sees salaries, others don't). |
DBMS — the matching benefits
| Benefit | Fixes |
|---|---|
| Minimal redundancy — single source of truth | Redundancy |
| Data consistency — centralized control | Inconsistency |
| Data integration & sharing | Isolation |
| Constraint enforcement | Integrity |
| Transactions (all-or-nothing) | Atomicity |
| Concurrency control | Concurrent-access anomalies |
| Granular access control | Security |
| Data independence + backup/recovery | Robustness |
Business impact (slide fact): ~60% fewer data errors and ~45% faster application development with a DBMS.