# 10 Carlyle Group SQL Interview Questions (Updated 2024)

Updated on

June 30, 2024

[Carlyle Group](https://www.Carlyle Group.com) employees write SQL queries for extracting investment data from multiple databases and analyzing complex financial trends in the private equity market. That's the reason behind why Carlyle Group typically asks SQL query questions in interviews for Data Science, Analytics, and & Data Engineering jobs.

As such, to help you prep for the Carlyle Group SQL interview, here’s 10 Carlyle Group SQL interview questions can you solve them?

## 10 Carlyle Group SQL Interview Questions

### SQL Question 1: Finding the Power Users from the "Investment" Database in the Carlyle Group

Given a database where each row records one investment done by a user, can you write a SQL query to find out power investors who have made more than 10000 USD total investment in any quarter of the year 2022?

##### Example Input:
investment_iduser_idinvestment_dateinvestment_amount
917122101/08/2022 00:00:005000
880222102/15/2022 00:00:006000
929358206/18/2022 00:00:007000
935222103/26/2022 00:00:002000
951798109/05/2022 00:00:003000

This SQL query groups each user's investment by quarter of the year 2022. It then sums up the for each user for each quarter and eliminates the results where the total investment amount is not greater than 10000. This query will help the Carlyle Group to identify their power investors who make significant investments each quarter. The query works by using the GROUP BY clause to partition the data by user_id and quarter, while the HAVING clause ensures that only those user-quarter pairs with total_investment greater than 10000 are included in the result.

To solve a related super-user data analysis question on DataLemur's free online SQL code editor, try this recently asked Microsoft SQL interview question:

### SQL Question 2: 2nd Largest Salary

Assume there was a table of Carlyle Group employee salary data. Write a SQL query to find the 2nd highest salary at the company.

#### Carlyle Group Example Input:

employee_idsalary
12500
2800
31000
41200

#### Example Output:

second_highest_salary
1200

You can solve this question interactively on DataLemur:

You can find a step-by-step solution here: 2nd Highest Salary.

### SQL Question 3: What is a SQL constraint?

The UNIQUE constraint is used to ensure the uniqueness of the data in a column or set of columns in a table. It prevents the insertion of duplicate values in the specified column or columns and helps to ensure the integrity and reliability of the data in the database.

For example, say you were on the Marketing Analytics team at Carlyle Group and were doing some automated keyword research:

Your keyword database might store SEO data like this:

In this example, the UNIQUE constraint is applied to the "keyword" field to ensure that each keyword is unique. This helps to ensure the integrity of the data in the database and prevents errors that could occur if two rows had the same keyword.

### SQL Question 4: Calculate Rank of Transactions based on Transaction Amounts

Carlyle Group is a multinational private equity, asset management, and financial services corporation. Considering this, a relevant problem might be to write a SQL query to calculate the rank of transactions for each client based on the transaction amounts.

We have the table to hold the transaction data, with the , , and columns.

##### Example Input:
transaction_idclient_idtransaction_datetransaction_amount
1001783205/08/20221500.00
1012456106/07/20223000.50
1056783210/08/20221750.75
1342456115/08/20223500.00
1589783220/08/20222000.00

The task is to write a SQL query to calculate the rank of transactions for each client based on the transaction amounts. The highest transaction amount should get the rank 1 and so on.

Expected output:

##### Example Output:
client_idtransaction_idtransaction_amountrank
783215892000.001
783210561750.752
783210011500.003
456113423500.001
456110123000.502

In PostgreSQL, you can accomplish this by using the window function. Here is a sample query:

In this query, the function is used with the clause to calculate the rank for each partition (client). The clause within the function specifies how to rank the rows in each partition. In this case, it orders the rows by in descending order. This means the transaction with the highest amount gets the rank 1, the second highest gets rank 2 and so on for each client.

Pro Tip: Window functions are a frequent SQL interview topic, so practice every window function problem on DataLemur

### SQL Question 5: How is the constraint used in a database?

The constraint is used to establish a relationship between two tables in a database. This ensures the referential integrity of the data in the database.

For example, if you have a table of Carlyle Group customers and an orders table, the customer_id column in the orders table could be a that references the id column (which is the primary key) in the Carlyle Group customers table.

### SQL Question 6: Retrieve Active and High Value Customers

For Carlyle Group, which is a global investment firm, we have a table where customer data is stored. This includes their ID, the date they became a customer, their total investments, and whether their account is active or not (Active = 1, Inactive = 0).

We want to find all customers who have been with the firm since before 2018, have invested more than \$10,000, and their accounts are still active.

##### Example Output:

This query uses the SQL command and the logical operators to filter the required records. This results in a list of customers who meet all the conditions: started their investments before 2018, have their total investment more than \$10,000, and their account is still active.

### SQL Question 7: Can you explain the difference between a foreign and primary key in a database?

To explain the difference between a primary key and foreign key, let's start with some data from Carlyle Group's marketing analytics database which stores data from Google Ads campaigns:

:

+------------+------------+------------+------------+ | ad_id | campaign_id| keyword | click_count| +------------+------------+------------+------------+ | 1 | 100 | Carlyle Group pricing | 10 | | 2 | 100 | Carlyle Group reviews | 15 | | 3 | 101 | Carlyle Group alternatives | 7 | | 4 | 101 | buy Carlyle Group | 12 | +------------+------------+------------+------------+

In this table, could be a primary key. It is unique for each row in the table and cannot contain null values.

could be a foreign key. It references the of the Google Ads campaign that each ad belongs to, establishing a relationship between the ads and their campaigns. This foreign key allows you to easily query the table to find out which ads belong to a specific campaign, or to find out which campaigns a specific ad belongs to.

It is also possible for a table to have multiple foreign keys that reference different primary keys in other tables. For example, the table could have additional foreign keys for the of the ad group that each ad belongs to, and the of the Google Ads account that the campaigns belong to.

### SQL Question 8: Calculate Average Investment Amount

Carlyle Group is an American multinational private equity, alternative asset management, and financial services corporation. As an interview question, you might be asked to calculate the average investment amount made by Carlyle Group for each sector they have invested in across all years.

Consider the following sample data for the problem:

##### Example Input:
investment_idsectorinvestment_dateinvestment_amount
001Energy01/10/20155000000
002Real Estate13/05/20178000000
003Energy05/12/20202000000
004Industrial30/08/20186000000
005Real Estate11/11/20209000000

We're interested in the average investment amount by Carlyle Group in each sector.

This query calculates the average () investment amount made by Carlyle Group in each sector. The clause is used to group the investment amounts by sector before the average is computed.

To practice a very similar question try this interactive LinkedIn Duplicate Job Listings Question which is similar for calculation across groups or this Amazon Average Review Ratings Question which is similar for calculating averages.

### SQL Question 9: Find the Maximum Investment in each Sector

The Carlyle Group is a global investment firm. They manage different funds investing in different sectors like Technology, Healthcare, Retail, etc. Each fund has multiple investments. Your task is to write a SQL query, which could give us the maximum investment made in each sector.

Given a table with columns , and an table with columns , , , write a query to get the maximum investment made in each sector.

Example Table:

fund_idsector
1Technology
2Healthcare
3Retail
4Automotive

Example Table:

investment_idfund_idinvestment_amount
10115000000
10213000000
10327000000
10432000000
10546000000
10628000000

This query first joins the and tables on the . Then it uses the clause to group the resulting data by . Next, for each group (i.e., each sector), it computes the maximum . This maximum amount is then returned as for each sector. Thus, providing the information on the maximum investment made in each sector.

### SQL Question 10: Can you explain the difference between and ?

The clause serves as a filter for the groups created by the clause, similar to how the clause filters rows. However, is applied to groups rather than individual rows.

For example, say you were a data analyst at Carlyle Group trying to understand how sales differed by region:

This query retrieves the total sales for all products in each region, and uses the clause to only sales made after January 1, 2023. The rows are then grouped by region and the clause filters the groups to include only those with total sales greater than \$400,000.

Check out the Carlyle Group career page and see what type of role you are best suited for!

### Carlyle Group SQL Interview Tips

The best way to prepare for a Carlyle Group SQL interview is to practice, practice, practice. In addition to solving the above Carlyle Group SQL interview questions, you should also solve the 200+ SQL questions on DataLemur which come from companies like FAANG tech companies and tech startups.

Each SQL question has multiple hints, fully explained answers along with a discussion board to see how others solved it and best of all, there is an interactive coding environment so you can easily right in the browser your query and have it graded.

To prep for the Carlyle Group SQL interview it is also wise to practice SQL problems from other investment management and private equity companies like:

However, if your SQL query skills are weak, forget about jumping right into solving questions – go learn SQL with this DataLemur SQL tutorial.

This tutorial covers things like aggregate functions and LEAD/LAG – both of these come up routinely during SQL job interviews at Carlyle Group.

### Carlyle Group Data Science Interview Tips

#### What Do Carlyle Group Data Science Interviews Cover?

In addition to SQL interview questions, the other types of questions to practice for the Carlyle Group Data Science Interview are:

• Statistics and Probability Questions
• Python or R Coding Questions
• Product Analytics Questions
• ML Interview Questions
• Behavioral Interview Questions

#### How To Prepare for Carlyle Group Data Science Interviews?

I'm sorta biased, but I think the best way to prep for Carlyle Group Data Science interviews is to read the book Ace the Data Science Interview.

The book solves 201 data interview questions taken from Facebook, Google & startups. It also has a crash course covering Product Analytics, SQL & ML. And finally it's vouched for by the data community, which is why it's earned 1000+ reviews on Amazon and a 4.5-star rating.