Oracle DB related questions with answers

Some very educative articles for trainees (and pros?):

• User Defined Encryption Questions for Your Next PL/SQL Developer Job Interview
• Addressing Security in Your Next PL/SQL Developer Job Interview
• Top 10 PL/SQL Developer Job Interview Questions to Demonstrate Your Coding Skill
• Top 5 SQL Questions for an Oracle Database PL/SQL Job Interview
  
• Oracle Technical Interview
• Oracle Technical Interview Questions Answered - Part 1
• Oracle Technical Interview Questions Answered - Part 2