Compare different database caching strategies.

Cache-Aside: application checks cache, on miss queries DB and populates cache. Simple but cache misses slow. Write-Through: writes go to cache and DB synchronously - consistent but slower writes. Write-Behind (Write-Back): writes to cache, async to DB - fast writes but potential data loss. Read-Through: cache handles DB reads transparently. Refresh-Ahead: predict and preload frequently accessed data. Consider: invalidation (TTL, events), consistency requirements, cache size, hit rate. Redis, Memcached commonly used.