Interview Questions

What do you understand about the strategy in backup and recovery strategy?

  • When there is a war, every army has a strategy to win it. A strategy is plan to achieve something. In oracle, DBA must create backup and recovery strategy in order to protect database against failure

Why backup monitoring is important even after scheduling backup scripts?

  • Monitoring must be done in order to make sure backups are running fine

What is the difference between Logical Backups and Physical Backups?

  • Logical is inside database, physical is outside database. Logical backups are taken using exp/imp or data pump utilities. Physical backups are taken using user managed backups or RMAN utility

Why RMAN is preferred over user managed backups?

  • User managed backups are old fashioned and takes OS level copy of files. RMAN is block level backup and it comes without any additional license. RMAN backup speed can be increased by allocating channels.
  • RMAN also offers incremental backup strategy which is not possible with user managed backups

Application user issued a wrong transaction which affected many tables in database. What will you do?

  • We need to check if we can flashback those tables, if not possible, we will discuss with application owner and Flashback entire database. But for this, Flashback database must be enabled at DB level. For flashback table, it is not needed.