ORACLE DATABASE INTERVIEW QUESTIONS

What is the purpose of the DISTINCT keyword in SQL?

How do you use the DISTINCT keyword in a SELECT statement in Oracle?

Can you use the DISTINCT keyword with multiple columns? If so, how?

How does the DISTINCT keyword affect the performance of a query in Oracle?

What is the difference between DISTINCT and GROUP BY in Oracle?

How do you use DISTINCT with an ORDER BY clause in Oracle?

How do you handle NULL values when using the DISTINCT keyword in Oracle?

How do you use DISTINCT in a subquery in Oracle?

How can you optimize queries that use the DISTINCT keyword in Oracle?

Explain a scenario where you need to use the DISTINCT keyword and how you would implement it in Oracle.