1. Which SQL command is used to retrieve data from a database?

2. Which keyword is used to eliminate duplicate values in SQL results?

3. Which SQL statement updates existing data in a table?

4. What does the BETWEEN operator do?

5. Which operator is used to combine multiple conditions in SQL?

6. Which command is used to remove a table from the database?

7. What is a foreign key?

8. Which SQL keyword is used to sort results?

9. Which SQL keyword is used to rename a column or table?

10. What does COMMIT do in SQL?

11. Which Oracle object stores data in rows and columns?

12. What is a deadlock in databases?

13. Which Oracle feature allows recovery of dropped tables?

14. What does ROLLBACK do?

15. Which Oracle background process is responsible for writing redo logs?

16. What is a synonym in Oracle?

17. What is an execution plan in SQL?

18. What is a primary key?