Hot backup, also known as dynamic or online backup, is a backup performed on data while the database is actively online and accessible to users.
A hot backup is the standard way to perform most database backups. Oracle is a leading provider of the process, but the company doesn’t have a monopoly on the concept. Oracle Recovery Manager (RMAN) is Oracle’s preferred backup method. A user can log into RMAN and instruct it to back up a database. RMAN can write backup sets to disk and tape.
Advantages and disadvantages of hot backup
Hot data backups can provide a practical solution in multi-user systems because they do not require downtime, unlike cold backups. Unlike hot backups, cold backups have a defined window in which to pause applications, shut down systems, and back up data.
But hot backup comes with some risks. If the data changes while the backup is in progress, the resulting copy may not match the final state of the data. Additionally, online backup consumes read IOPS and can impact database performance if performed when data storage is already powered on. Users may notice the hit as a temporary system or network slowdown.
Use case for hot backup
When deciding the type of backup, an IT admin must weigh the downtime, but comprehensive nature, of a cold backup with the ability to keep applications available and productive with a hot data backup.
A hybrid backup option uses application-aware snapshots and application-aware data protection, creating momentary pause and application downtime. The application continues to run, creating a virtual backup window.
When planning backup or disaster recovery (DR) sites, especially for failover and hot backup situations, it is important to consider the geographic scope of potential disasters. Business continuity and disaster recovery professionals should look for sites that are at least 100 miles apart. This prevents local or regional disasters from destroying a backup site as well as the primary site.