Databases & System Design•Part 4: In-Memory Caching & Fast Data Stores (Redis) (41 - 50)
When Redis caching is architectural overkill:
In Simple Words: When an app has low traffic (< 50 req/sec), queries are already sub-10ms with proper indexing, or data changes so fast that cache invalidation overhead outweighs gains.
sql
-- Often a fast PostgreSQL index is faster & simpler than caching in Redis:
-- Average query time: 0.8ms without maintaining Redis cache invalidation logic!
SELECT * FROM products WHERE sku = 'SKU-8821';