Database Diagrams

Databases are the foundation of nearly every application, and understanding how they handle data at scale separates engineers who debug by intuition from those who debug by design. This collection of 20 free Mermaid diagrams covers the core concepts you'll encounter when building, scaling, or operating production database systems.

Start with the fundamentals of high availability: Database Replication shows how data is copied across nodes, while Primary Replica Sync traces the step-by-step message exchange between leader and follower. For scaling reads and writes independently, Read Write Splitting and Database Sharding illustrate the routing logic involved.

Transactional correctness is covered in depth: Transaction Lifecycle walks through begin, execute, and commit phases, while ACID Properties maps atomicity, consistency, isolation, and durability to concrete behaviors. Distributed transactions are handled by Two Phase Commit. Concurrency control is explained in MVCC Workflow.

Caching strategies — Cache Aside Pattern, Write Through Cache, and Write Back Cache — show how applications layer fast storage in front of persistent databases. Operational topics like Database Failover, Backup and Restore Flow, and Database Migration Workflow round out the collection. Every diagram is free to edit and export in Graphlet.