Does caching personal data create UK GDPR obligations?

Yes — if Redis caches personal data (session tokens linked to user accounts, search results containing names/addresses), it is processing personal data under UK GDPR. Key obligations: TTL (Time to Live) must enforce data minimisation — session tokens should expire after the session; cached search results should expire after a reasonable period. UK GDPR right to erasure: if you cache personal data, you must be able to invalidate that cache entry on erasure request.

Should I use Redis as a database or just for caching?

Redis as primary database (Redis Stack with Redis OM): works well for leaderboards, real-time analytics, and session management. Not recommended as a primary database for transactional data that requires ACID guarantees (use PostgreSQL). ClickMasters recommendation: Redis for caching, session storage, rate limiting, pub/sub, and sorted set use cases. PostgreSQL for transactional data.

Redis Vs Memcached Uk

Redis vs Memcached for UK Software Development — Honest Comparison (2025)

Updated: June 20259 min read

🇬🇧 UK💷 GBP📊 Comparison🔒 UK GDPR⚖️ UK Law

Direct Answer

Redis is the right default for virtually all UK software projects: data structure richness (sorted sets, pub/sub, streams), persistence options, Lua scripting, and the largest UK developer community. Memcached is only worth considering for the simplest key-value caching at extreme throughput — a scenario almost no UK project encounters. ClickMasters uses Redis (AWS ElastiCache for Redis) on all projects. Redis vs Memcached is one of the shorter technology comparisons — Redis has largely won for UK software development. This guide explains why and covers the UK-specific considerations (UK GDPR for cached personal data, ElastiCache pricing).

Factor	Redis (AWS ElastiCache)	Memcached (AWS ElastiCache)
Data structures	✅ Strings, hashes, lists, sets, sorted sets, streams	Strings only (key-value)
Persistence (AOF/RDB)	✅ Optional — survive restarts	None — data lost on restart
Pub/Sub messaging	✅ Built-in — useful for real-time features	Not available
Lua scripting	✅ Atomic scripts	Not available
Cluster mode	✅ Redis Cluster (horizontal sharding)	✅ Multi-threading + horizontal
UK GDPR — personal data TTL enforcement	✅ TTL per key — enforce retention limits	✅ TTL per key — same capability
Session storage	✅ Standard choice	Possible but less feature-rich
Rate limiting (API / FCA)	✅ Sorted sets + INCR pattern — elegant	Possible but verbose
AWS managed service	ElastiCache for Redis	ElastiCache for Memcached
ClickMasters default	✅ All projects	Never — use Redis instead