juniorCaching
Explain the 'Write-Through' cache strategy.
Updated Apr 28, 2026
Short answer
Data is written to both the cache and the permanent database simultaneously.
Deep explanation
Caching is essential for performance optimization. Data is written to both the cache and the permanent database simultaneously. By reducing the need to access slower storage layers (like HDDs or remote databases), systems can achieve much lower latency.
Real-world example
Storing the results of a complex database query in Redis.
Common mistakes
- Not setting a TTL, leading to the cache growing indefinitely or serving very old data.
Follow-up questions
- Is cache persistent?