Redis vs MySQL
A side-by-side technical matrix of Redis (Databases & Cache) and MySQL (Databases & Cache) — summaries, strengths and structural trade-offs, symmetrically laid out.
Redis
Redis is an in-memory data store used as a cache, message broker, and session store, with data structures like sorted sets and streams. Sub-millisecond reads make it the default choice for hot-path data.
Pros
- Sub-millisecond latency. In-memory storage answers reads faster than any disk database. 0
- Rich data structures. Sorted sets, streams, and pub/sub solve queues and leaderboards natively. 0
- Simple protocol. Every language has a mature, easy client library. 0
- Proven at scale. Cluster mode shards data across nodes transparently. 0
Cons
- RAM-bound cost. Dataset size is capped by expensive memory, not cheap disk. 0
- Weak durability defaults. Crash recovery can lose recent writes unless AOF is tuned. 0
- Single-threaded core. One slow command blocks every other operation. 0
- License turbulence. The 2024 license change spawned the Valkey fork and ecosystem split. 0
MySQL
MySQL is the world's most widely deployed open-source relational database, prized for speed and simplicity. It anchors the classic LAMP stack and most shared hosting.
Pros
- Ubiquitous. Runs on virtually every host and cloud with mature tooling. 0
- Fast reads. Well-tuned read paths make it excellent for read-heavy web apps. 0
- Easy to operate. Simple replication and a shallow learning curve. 0
- Proven at scale. Powers Facebook, YouTube, and countless web platforms. 0
Cons
- Weaker SQL. Fewer advanced features than PostgreSQL for complex queries. 0
- Oracle stewardship. Ownership concerns pushed many teams toward MariaDB. 0
- Historical quirks. Silent data truncation and loose typing bite the unwary. 0
- Limited extensions. No rich extension ecosystem like Postgres offers. 0