A developer detailed their experience replacing Redis with PostgreSQL, achieving faster combined operations and significant cost savings. The author identified three core Redis use cases—caching, pub/sub, and job queues—and mapped them to native PostgreSQL features. For caching, they used UNLOGGED tables for high-speed writes that don't survive crashes, ideal for temporary data.

Pub/sub was handled via PostgreSQL's LISTEN/NOTIFY mechanism, which offers atomic notifications within database transactions. Job queues were implemented using the SKIP LOCKED feature, enabling a lock-free queue system for concurrent workers. The primary motivations were cost reduction (saving ~$100/month by eliminating AWS ElastiCache) and operational simplicity (reducing two databases to one).

While individual operations in PostgreSQL were 50-160% slower than Redis, combined operations (e.g., insert data, invalidate cache, notify subscribers) were faster due to the elimination of network hops. This architectural shift is best suited for small-to-medium applications prioritizing simplicity and transactional integrity over extreme throughput.