Asynchronous Replication:?

Short answer: Data is written to the primary database, and changes are replicated to secondary databases after a delay.

Explain a bit more

Advantages: Better performance due to less replication overhead. Disadvantages: Potential for data loss or inconsistency in the event of a failure. Tools for Replication: SQL Server: Use Always On Availability Groups or Transactional Replication. PostgreSQL: Use Streaming Replication or Logical Replication. MySQL: Use MySQL Replication or Group Replication. MongoDB: Use Replica Sets for automatic failover and high availability. Example (PostgreSQL Streaming Replication): # On Master Node wal_level = replica archive_mode = on archive_command = 'cp %p /var/lib/postgresql/archive/%f' # On Standby Node primary_conninfo = 'host=master_ip port=5432 user=replication_user password=replication_password' Database Scaling & Performance

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.