Replication Metrics:?

Short answer: For distributed systems, monitor the lag between the primary database and read replicas. Tools for Monitoring: New Relic, Datadog, SolarWinds, pg_stat_activity (for PostgreSQL), SHOW STATUS (for MySQL), or SQL Server Profiler for SQL Server.

Real-world example (ShopNest)

ShopNest’s SQL Server database stores customers, products, and orders. Good indexes and clear foreign keys keep checkout queries fast and safe.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.