Read-only database copies for improved performance

What is a Read Replica?

A copy of your database that handles READ operations only, allowing you to isolate heavy read workloads from your main production database.

Key Use Case

Problem: Analytics queries slow down main production database Solution: Setup Read Replica for analytics queries

Main DB → Production traffic (fast)
Read Replica → Analytics queries (isolated)

Result: Users' experience not impacted

Asynchronous Replication

How it works:

Main DB: Saves data immediately ✅
    ↓
    "I'm done!" (doesn't wait)
    ↓
Replica: Gets data a few seconds later ⏱️

• Main DB doesn't wait for replica
• Replica syncs in the background
• Small delay (eventual consistency)

Replication Lag

The Delay:

• Writes to Main DB: Instant (saved immediately)
• Updates to Replica: 2-3 second delay