Data Management, Storage and Security
Data management
Understand how data is organised: characters, fields, records, files and databases. Know the purpose of a database management system, primary and foreign keys, and why normalisation reduces duplication and inconsistency. Be able to describe validation (range, type, presence, length checks) versus verification (double entry, visual checking) and explain that validation prevents unreasonable data while verification catches transcription errors.
Storage and backup
Compare local, network and cloud storage on capacity, cost, access speed, availability and security. Know the 3-2-1 backup rule and the difference between a backup (restorable copy) and synchronisation (mirroring, which propagates deletions and ransomware). Understand redundancy (RAID) versus backup: RAID protects against drive failure, not against accidental deletion or malware.
Security
Name the threats (malware, phishing, ransomware, social engineering, insider misuse, physical theft) and controls (strong authentication and multi-factor authentication, access levels based on least privilege, encryption at rest and in transit, firewalls, patching, audit logs, staff training). Distinguish authentication from authorisation, and confidentiality, integrity and availability as the goals of security.
Traps in questions
- Calling a synced folder a backup.
- Confusing validation with verification.
- Believing encryption stops data being stolen; it protects confidentiality if the key is safe.
- Forgetting human factors: phishing defeats good technology through user error.
- Ignoring privacy principles such as collecting only necessary data and limiting retention.
Worked rule of thumb
For any scenario, answer in three layers: identify the asset and its value, name the threat and likelihood, then select a proportionate control and say how it will be tested. Proportionate means the cost of the control should not exceed the value at risk.