DBA Interview Questions and Answers

• Suppoce one of the your end user come to you and told you that his report is hanged what should you do?
  
  
• If you database is in no archivelog mode and you took backup yesterday and your database size is 40gb very next day when you start database that time it gives error that one of the redolog file corrupted how can you recovered it?
  
  
• What is the buffer busy wait?
  
  
• when data block buffer has too many contention what to do?
  
  
• what is the localy managed tablespace?
  
  
• why freelist contention is occured?
  
  
• what is the row chaining and row migration? How can you judged it and tune it?
  
  
• if your database size is more than the 100gb and running 24*7*365 how planned to decide to take backup?
  
  
• what is the rollback segment contention?
  
  
• why we used undo_retention?
  
  
• if you got ora-1555 error snapshot too old what to do?
  
  
• If you give proper hint in sql query but when you check from the trace that hint is not working why?
  
  
• Give the parameter which is affected on Oracle block size.
  
  
• What is the pctthreshold?
  
  
• If you want to check disk io how to obtained it?
  
  
• To avoid sorting what to do?
  
  

Answers