Read Replica

ELI5 — The Vibe Check

A read replica is a copy of your database that only handles read queries. It's like hiring extra librarians who can look stuff up but can't add or remove books. Only the main database (primary) handles writes, then copies the changes to all the replicas. Great for when your app does way more reading than writing.

Real Talk

A read replica is a secondary database instance that asynchronously or synchronously replicates data from a primary instance. All write operations go to the primary, while read queries are distributed across replicas to reduce primary load. Replication lag means replicas may serve slightly stale data. Most managed database services support easy read replica provisioning.

When You'll Hear This

"We added three read replicas to handle the dashboard traffic." / "Read replicas have slight replication lag, so don't read-after-write from them."