Read Replicas & Scaling Reads

Summary

Creating read-only copies of a database to offload read traffic from the primary instance — a common pattern for read-heavy applications, distinct from the failover-focused replication in high availability.

• 1Create a read replica of a sample database and route a read query to it.
• 2Learn why read replicas introduce replication lag and why that matters for consistency-sensitive reads.
• 3Understand the difference between scaling reads (replicas) and scaling writes (sharding, a harder problem).