Amazon SQL Interview Questions

Amazon, one of the most sought-after and renowned FAANG companies, has a spectrum of opportunities to offer. And like any other tech giant, Amazon also receives a huge amount of applications from around the globe. The journey to get past the competition and land a job at Amazon is challenging. So, if you are a software engineer, a software developer, a data engineer, an engineering manager, or a tech lead gunning for a job at Amazon, then this article is for you!

If you are preparing for a tech interview, check out our interview questions page and salary negotiation ebook to get interview-ready! Also, read Amazon Leadership Interview Questions and Amazon System Design Interview Questions for specific insights and guidance on Amazon Tech interviews.

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We are here to make the exhaustive process of preparing for a tech interview or a coding interview easier for you. Before we dive into the process, remember this: preparation is the key to success.

In this article, we’ll cover:

1. Amazon interview process for data engineers
2. Most commonly asked Amazon interview questions on SQL
3. Practice problems for Amazon SQL interviews
4. Tips to prepare for SQL interview for Amazon
5. FAQs About Amazon SQL interviews
   

Amazon Interview Process for Data Engineers

Amazon has an elaborate interview procedure similar to other FAANG companies. However, with increasing seniority of the position, the interview process becomes more stringent and gruesome. The entire Amazon SQL Interview process can be divided into three stages:

1. Phone Screen

After your profile is shortlisted, phone screening is the preliminary round of the interview process. The questions at the phone interview will be related to your resume and skills. This stage of the Amazon SQL Interview process is more focused on understanding the applicant compared to their technical proficiency.

2. Technical Interview

Technical interview questions for Amazon are mostly related to coding, algorithms, and machine learning. You will be assigned 1 or 2 problems to solve within a stipulated amount of time.

If you are planning to apply for any of the data science positions or the positions of business analyst, business intelligence engineer, software engineer, software developer, and tech lead, then a technical interview on SQL will be a part of the process.

Refer to the Problems page for a list of commonly asked problems and solutions.

3. On-site Interview

The final and most challenging round of the Amazon SQL Interview process is the on-site interview, also known as “The Loop.” There can be 3-5 rounds, where each round goes on for about 45 minutes and is extremely exhausting.

The loop can be further broken down into 3 types of rounds:

1. Coding round: The primary focus of this round is to gauge an idea of the candidate's technical expertise. You will be assigned 1 or 2 coding problems, and your approach towards solving them would be analyzed.

2. Behavioral round: It is one of the integral rounds of all on-site interviews and is based on Amazon’s 14 leadership principles.

3. The Bar raiser round: This round is the final filter round. At the end of the round, only handpick candidates that pass the assessment of Amazon’s trained recruiters get selected.

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Common SQL Interview Questions for Amazon

This section will serve as your “go-to SQL interview prep guide,” as we have covered the most commonly asked SQL interview questions at Amazon. In addition to getting well-versed in Amazon SQL interview questions, it is also suggested to brush up on your problem-solving skills, as it comes in handy during FAANG interviews.

1. How would you explain SQL to a person with no technical knowledge?

Sample answer: SQL stands for Structured Query Language, and as the name suggests, it is a language used by database administrators to communicate with the database. The administrator inputs a query in the form of a string of commands to search for values in a database.

2. What is the Amazon database?

Sample answer: Amazon database is one of the Amazon Web Services, which is a fully managed petabyte-scale data warehouse service. There are various Amazon Database Services available, such as DynamoDB, RDS, ElastiCache, and RedShift.  

3. What is DynamoDB Auto Scaling?

Sample answer: Auto Scaling is a specialized feature of DynamoDB that allows it to automatically scale up and down the global secondary index or its own read and write.

4. Which of the four available AWS services will you choose from for collecting and processing e-commerce data for real-time analysis?

Sample answer: For collecting and processing E-Commerce data for real-time analysis, I’ll use DynamoDB. DynamoDB is a fully managed NoSQL database service that can be used for any type of unstructured data and can also be used for the data taken from e-commerce websites.

5. What is an Inner Join?

Sample answer: Inner join is the default join, which is used when no join is specified.

6. What is a full outer join in SQL?

Sample answer: The full outer join returns all the rows from both the tables, inserting NULLs in places where no matching rows exist and matching up the rows where a match can be made.

7. Which is the only constraint that works at the column level?

Sample answer: The only constraint that works at the column level is NOT NULL.

8. After using the ALTER command, can a rollback be performed?

Sample answer: No, a rollback cannot be performed, as ALTER is a DDL command, and when the DDL statements are executed, the oracle server performs an automatic COMMIT.

9. What are some examples of pseudocolumns in SQL?

Sample answer: ROWNUM, ROWID, and USER are some examples of pseudocolumns in SQL.

10. Write a command to change the password of the user x from "abcd" to "dfgh."

Sample answer: ALTER USER x IDENTIFIED BY dfgh

11. What is a leader node and a computer node?

Sample answer: In a leader node, the queries from the client applications are received, whereas in a computer node, the steps assigned in the leader node are executed, and the data gets transmitted.

Practice Problems for Amazon SQL Interviews

Irrespective of what your specialization is, tech interviews always feature some coding problems. We have uploaded numerous solved practice problems on our website for your reference. Here, we have mentioned a few important ones here for your reference:

1. Write a program to find if a number or a string is a palindrome or not. (Solution)  
2. Implement a Min Stack that would support push, pop methods, and one method that returns the minimum element in the entire stack.  (Solution)
3. Check if the given binary tree is a binary search tree. (Solution)

Tips to Prepare for SQL Interview Questions at Amazon

Few pointers to remember while preparing for SQL interview questions are:

1. Brush up on your basics! Getting your fundamentals strong would ensure a good start to your preparation.
2. Get acquainted with the basic syntax, sub-queries, and queries of SQL.
3. Expand your knowledge about Amazon, its services, and core values.
4. Do not give up! The entire process might seem intimidating and exhausting, but the result is worth the struggle.

All Set to Crack Your Next Amazon SQL Interview?

Since its inception in 2014, Interview Kickstart has helped thousands of experienced engineers achieve their dream jobs.

We aim to help engineers get acquainted with their chosen field’s intricacies and provide them with all the required guidance to ace their interviews with tech giants. Our programs are tailored to specific domains, including Data Engineering, so that you can sail through every round of the interview.

Clearing an interview requires much more than sound technical knowledge —  so, we train you in a manner that helps you develop a winner's stride. IK is the golden ticket for all the budding engineers who wish to land the job they deserve.

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FAQs About Amazon SQL Interview

Q1. What are the three stages of the Amazon SQL Interview?

The SQL interviews in Amazon are lengthy and require strenuous efforts. However, the SQL Amazon interview is unavoidable for all data engineers. The interview is divided into three rounds: Preliminary Phone Interview, Technical Interview, The Loop. The loop is the most challenging stage of the interview process that requires preparation and patience.

Q2. Do I need to read Amazon Leadership Principles for the technical interview?

Yes, as behavioral interviews form an integral part of Amazon’s recruitment process. The answer to the behavioral interview questions serves as the key to understanding your personality, social-interaction skills, and teamwork. You can refer to 35 Amazon Leadership Principle Interview Questions and Amazon Behavioral interview questions to prepare for your SQL Amazon interview.

Q3. Does Amazon use SQL or NoSQL?

Amazon uses DynamoDB, a proprietary NoSQL database, along with Oracle and MySQL for specific purposes, ensuring scalability and performance in product information storage.

Q4. How many people pass interview at Amazon?

The success rate, or the proportion of applicants who get a job offer after the Amazon Loop interview, is 20%, according to Misha Yurchenko, the author of "Cracking the Code."

Q5. What is the average Data Engineer salary at Amazon?

In the US, the average annual salary for an Amazon.com data engineer is around $141,563, which is 12% more than the national average. (Source: Indeed.com)