Which statement correctly describes hot standby?

• A. Hot standby runs concurrently and failover occurs immediately
• B. Cold standby is ready to take over instantly
• C. Hot standby uses manual intervention to switch over
• D. Cold standby requires continuous power to be active

Answer: (A)

Hot standby means a duplicate system runs in parallel with the active one and stays in sync, so if the primary fails the backup can take over immediately. This automatic failover minimizes downtime because there’s no waiting for manual startup or data restoration—the standby is already up and ready to handle requests.

This differs from cold standby, where the backup isn’t running or is not ready to take over right away, so bringing it online and getting it synchronized takes time and effort. The idea that hot standby requires manual intervention is not correct; the strength of hot standby is automatic failover. Also, cold standby does not require continuous power to be active in the sense of being ready to serve; it’s typically powered down and activated only when needed, which is why the standby isn’t immediately available. Hot standby delivers near-instant failover, at the cost of keeping a full duplicate system running.