Oracle SQL Interview Questions

Oracle is one of the largest database software firms in the world, offering a wide spectrum of services including enterprise software solutions, cloud systems and CRM softwares. Since SQL is a widely used language to process data in relational databases and Oracle is the biggest name in the database software space, the company actively hires SQL developers for roles largely pertaining to data analysis and data science. In fact, Oracle has a dedicated Integrated Development Environment called the Oracle SQL Developer, meant specifically for leveraging SQL in Oracle databases.

Expertise in SQL is required for data analyst and data engineering roles at Oracle. Oracle usually hires experienced professionals for these roles, although freshers can also be hired for more junior data analyst roles.

In this article, we’ll look at some SQL questions that are commonly asked in Oracle’s SQL developer and Data Analyst interviews. These questions will give an idea of what type of questions to expect at the interview so that you can structure your prep accordingly.

What we’ll cover:

• Topics to prepare for the Oracle SQL interview
• Oracle SQL interview questions
• Tips to crack the Oracle SQL interview
• Scale-up your professional career

Topics to Prepare for the Oracle SQL Interview

The questions/problems asked at Oracle SQL interviews are typically based on the following set of topics:

• Normalization
• Indexes
• Partitions
• Working with SQL and No-SQL databases
• Aggregate functions
• Nested queries
• ACID transitions
• Data modelling
• Start and snow-flake schema
• Table types
• SQL performance tuning
  

What to Expect at the Oracle SQL Developer Interview

Here’s typically what you can expect at the interview:

• Technical SQL questions: These mostly pertain to core concepts in SQL and general features of certain SQL queries.
• Problem-based SQL questions: You’ll be asked to solve one or two problems, where you’ll be given a dataset and asked to achieve a set of results using appropriate SQL queries.
• Qualitative analysis: You’re asked to solve a problem based on statistics. Your ability to analyze data and understand the statistical significance of datasets is tested.
• Behavioral round: You’re asked questions on workplace situations, workplace conduct, ethics, professional attitude, and work-life balance.

Oracle SQL Interview Questions

Following is a list of SQL interview questions that you can practice while preparing for your interview at Oracle:

1. What are some tips to improve the overall performance of SQL queries?
2. What are some aspects that can negatively impact the performance of a database system?
3. What is the Explain Plan in an Oracle database?
4. Explain the process of tuning a query using the Explain Plan.
5. Explain the difference between cost-based and rule-based optimizers.
6. Explain the bottlenecks that cause an SQL query to run much slower than usual? How do you optimize the performance in such cases?
7. Explain the differences between Proactive and Reactive Tuning.
8. Explain some performance tuning enhancements for Oracle databases.
9. Explain the process of Pattern Matching in SQL?
10. Explain the function of sqlnet.ora with an example.
11. Explain the various types of backups available in Oracle.
12. Explain the process of monitoring space allocations in database servers.
13. Explain the differences between OLTP and OLAP.
14. Explain the Aggregate and Scalar functions in SQL.
15. Explain the various forms of normalization.
16. What are some advantages of using packages in SQL?
    

Some problem-related questions:

17. You’re given a table of the number of interactions a bunch of students have had with 30 colleges. Find the top 10 colleges that the average student interacted with.
18. You’re given a set of items that customers purchased over the last 2 days. Find the top 3 most purchased items over the last two days.  
19. Import a huge data-set with duplicates into a warehouse while meeting the requirements of a business intelligence designer for query speed.
20. You’re given the average interactions of customers who visited an ecommerce site and bought a set of items. Find the top 3 customers with the most interactions.
    

For more Oracle interview questions, check out 40+ Oracle Technical Interview Questions.

Tips to Crack the Oracle SQL Developer Interview Process

• Master the basics: Especially when dealing with SQL, having a strong grip on the fundamentals is supremely important. Oftentimes, things can go south for candidates who are well-prepared but don’t have a strong hold of the fundamentals.
• Practice queries thoroughly: Make sure to practice your queries and not know them only in theory. You will be asked to implement queries on random SQL tests cases, so being sure what query to use when is extremely important.
• Be honest with your SQL knowledge and capabilities: When you’re asked a question in the interview that you don’t have an answer to or don’t know how to proceed, be honest. Honesty is awarded more points than attempting something you claimed to have known but couldn’t deliver.
• Practice mock interviews: With mock interviews, you can get better and better at interviewing, as you can constantly make improvements in the areas where you’re lacking through good feedback. Practicing with the right professionals who have the ability to give proper feedback is extremely important, as without the right feedback, there will be little to no improvement.  
  

At Interview Kickstart, you can learn from and practice mock interviews with actual hiring managers and tech leads from FAANG and Tier-1 tech companies like Oracle. To learn more about what our programs offer, join our FREE webinar today!

• Don’t neglect behavioral interviews: Behavioral interviews are highly influential in hiring decisions for roles across the board. Make sure you prepare answers to commonly asked questions and don’t go unprepared, for recruiters take candidate performances in behavioral interviews very seriously.
  

Recommended reading: 9 Behavioral Questions for Your Next Big Interview

Ready for Your Next Interview at Oracle?

Interview prep can be daunting. It requires hard work, the right strategic plan, and a lot of practice. If you need a guide, join Interview Kickstart! We have helped over 6,000 engineers crack the toughest tech interviews and land their dream jobs. Here’s what our alums have to say about our program:

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