๐ ๐ฎ๐๐๐ฒ๐ฟ ๐ฆ๐ค๐ ๐ณ๐ผ๐ฟ ๐๐ฎ๐๐ฎ ๐๐ป๐ฎ๐น๐๐๐ถ๐ฐ๐ ๐ถ๐ป ๐๐๐๐ ๐ญ๐ฐ ๐๐ฎ๐๐!๐
Want to become a SQL pro in just 2 weeks?
SQL is a must-have skill for data analysts! ๐ฏ
This step-by-step roadmap will take you from beginner to advanced ๐
๐๐ข๐ง๐ค๐:-
https://pdlink.in/3XOlgwf
๐ Follow this roadmap, practice daily, and take your SQL skills to the next level!
Want to become a SQL pro in just 2 weeks?
SQL is a must-have skill for data analysts! ๐ฏ
This step-by-step roadmap will take you from beginner to advanced ๐
๐๐ข๐ง๐ค๐:-
https://pdlink.in/3XOlgwf
๐ Follow this roadmap, practice daily, and take your SQL skills to the next level!
Python for Data Engineering role ๐
โ List Comprehensions and Dict Comprehensions
โณ Optimize iteration with one-liners
โณ Fast filtering and transformations
โณ O(n) time complexity
โ Lambda Functions
โณ Anonymous functions for concise operations
โณ Used in map(), filter(), and sort()
โณ Key for functional programming
โ Functional Programming (map, filter, reduce)
โณ Apply transformations efficiently
โณ Reduce dataset size dynamically
โณ Avoid unnecessary loops
โ Iterators and Generators
โณ Efficient memory handling with yield
โณ Streaming large datasets
โณ Lazy evaluation for performance
โ Error Handling with Try-Except
โณ Graceful failure handling
โณ Preventing crashes in pipelines
โณ Custom exception classes
โ Regex for Data Cleaning
โณ Extract structured data from unstructured text
โณ Pattern matching for text processing
โณ Optimized with re.compile()
โ File Handling (CSV, JSON, Parquet)
โณ Read and write structured data efficiently
โณ pandas.read_csv(), json.load(), pyarrow
โณ Handling large files in chunks
โ Handling Missing Data
โณ .fillna(), .dropna(), .interpolate()
โณ Imputing missing values
โณ Reducing nulls for better analytics
โ Pandas Operations
โณ DataFrame filtering and aggregations
โณ .groupby(), .pivot_table(), .merge()
โณ Handling large structured datasets
โ SQL Queries in Python
โณ Using sqlalchemy and pandas.read_sql()
โณ Writing optimized queries
โณ Connecting to databases
โซ Working with APIs
โณ Fetching data with requests and httpx
โณ Handling rate limits and retries
โณ Parsing JSON/XML responses
โฌ Cloud Data Handling (AWS S3, Google Cloud, Azure)
โณ Upload/download data from cloud storage
โณ boto3, gcsfs, azure-storage
โณ Handling large-scale data ingestion
๐๐ก๐ ๐๐๐ฌ๐ญ ๐ฐ๐๐ฒ ๐ญ๐จ ๐ฅ๐๐๐ซ๐ง ๐๐ฒ๐ญ๐ก๐จ๐ง ๐ข๐ฌ ๐ง๐จ๐ญ ๐ฃ๐ฎ๐ฌ๐ญ ๐๐ฒ ๐ฌ๐ญ๐ฎ๐๐ฒ๐ข๐ง๐ , ๐๐ฎ๐ญ ๐๐ฒ ๐ข๐ฆ๐ฉ๐ฅ๐๐ฆ๐๐ง๐ญ๐ข๐ง๐ ๐ข๐ญ
Join for more data engineering resources: https://t.me/sql_engineer
โ List Comprehensions and Dict Comprehensions
โณ Optimize iteration with one-liners
โณ Fast filtering and transformations
โณ O(n) time complexity
โ Lambda Functions
โณ Anonymous functions for concise operations
โณ Used in map(), filter(), and sort()
โณ Key for functional programming
โ Functional Programming (map, filter, reduce)
โณ Apply transformations efficiently
โณ Reduce dataset size dynamically
โณ Avoid unnecessary loops
โ Iterators and Generators
โณ Efficient memory handling with yield
โณ Streaming large datasets
โณ Lazy evaluation for performance
โ Error Handling with Try-Except
โณ Graceful failure handling
โณ Preventing crashes in pipelines
โณ Custom exception classes
โ Regex for Data Cleaning
โณ Extract structured data from unstructured text
โณ Pattern matching for text processing
โณ Optimized with re.compile()
โ File Handling (CSV, JSON, Parquet)
โณ Read and write structured data efficiently
โณ pandas.read_csv(), json.load(), pyarrow
โณ Handling large files in chunks
โ Handling Missing Data
โณ .fillna(), .dropna(), .interpolate()
โณ Imputing missing values
โณ Reducing nulls for better analytics
โ Pandas Operations
โณ DataFrame filtering and aggregations
โณ .groupby(), .pivot_table(), .merge()
โณ Handling large structured datasets
โ SQL Queries in Python
โณ Using sqlalchemy and pandas.read_sql()
โณ Writing optimized queries
โณ Connecting to databases
โซ Working with APIs
โณ Fetching data with requests and httpx
โณ Handling rate limits and retries
โณ Parsing JSON/XML responses
โฌ Cloud Data Handling (AWS S3, Google Cloud, Azure)
โณ Upload/download data from cloud storage
โณ boto3, gcsfs, azure-storage
โณ Handling large-scale data ingestion
๐๐ก๐ ๐๐๐ฌ๐ญ ๐ฐ๐๐ฒ ๐ญ๐จ ๐ฅ๐๐๐ซ๐ง ๐๐ฒ๐ญ๐ก๐จ๐ง ๐ข๐ฌ ๐ง๐จ๐ญ ๐ฃ๐ฎ๐ฌ๐ญ ๐๐ฒ ๐ฌ๐ญ๐ฎ๐๐ฒ๐ข๐ง๐ , ๐๐ฎ๐ญ ๐๐ฒ ๐ข๐ฆ๐ฉ๐ฅ๐๐ฆ๐๐ง๐ญ๐ข๐ง๐ ๐ข๐ญ
Join for more data engineering resources: https://t.me/sql_engineer
๐3
๐ณ ๐๐ฅ๐๐ ๐ ๐ถ๐ฐ๐ฟ๐ผ๐๐ผ๐ณ๐ ๐๐ฒ๐ฟ๐๐ถ๐ณ๐ถ๐ฐ๐ฎ๐๐ถ๐ผ๐ป ๐๐ผ๐๐ฟ๐๐ฒ๐๐
Master Data Analytics in 2025!
These 7 FREE courses will help you master Power BI, Excel, SQL, and Data Fundamentals!
๐๐ข๐ง๐ค ๐:-
https://pdlink.in/4iMlJXZ
Enroll For FREE & Get Certified ๐
Master Data Analytics in 2025!
These 7 FREE courses will help you master Power BI, Excel, SQL, and Data Fundamentals!
๐๐ข๐ง๐ค ๐:-
https://pdlink.in/4iMlJXZ
Enroll For FREE & Get Certified ๐
5 frequently Asked SQL Interview Questions with Answers in Data Engineering interviews:
๐๐ข๐๐๐ข๐๐ฎ๐ฅ๐ญ๐ฒ - ๐๐๐๐ข๐ฎ๐ฆ
โซ๏ธDetermine the Top 5 Products with the Highest Revenue in Each Category.
Schema: Products (ProductID, Name, CategoryID), Sales (SaleID, ProductID, Amount)
WITH ProductRevenue AS (
SELECT p.ProductID,
p.Name,
p.CategoryID,
SUM(s.Amount) AS TotalRevenue,
RANK() OVER (PARTITION BY p.CategoryID ORDER BY SUM(s.Amount) DESC) AS RevenueRank
FROM Products p
JOIN Sales s ON p.ProductID = s.ProductID
GROUP BY p.ProductID, p.Name, p.CategoryID
)
SELECT ProductID, Name, CategoryID, TotalRevenue
FROM ProductRevenue
WHERE RevenueRank <= 5;
โซ๏ธ Identify Employees with Increasing Sales for Four Consecutive Quarters.
Schema: Sales (EmployeeID, SaleDate, Amount)
WITH QuarterlySales AS (
SELECT EmployeeID,
DATE_TRUNC('quarter', SaleDate) AS Quarter,
SUM(Amount) AS QuarterlyAmount
FROM Sales
GROUP BY EmployeeID, DATE_TRUNC('quarter', SaleDate)
),
SalesTrend AS (
SELECT EmployeeID,
Quarter,
QuarterlyAmount,
LAG(QuarterlyAmount, 1) OVER (PARTITION BY EmployeeID ORDER BY Quarter) AS PrevQuarter1,
LAG(QuarterlyAmount, 2) OVER (PARTITION BY EmployeeID ORDER BY Quarter) AS PrevQuarter2,
LAG(QuarterlyAmount, 3) OVER (PARTITION BY EmployeeID ORDER BY Quarter) AS PrevQuarter3
FROM QuarterlySales
)
SELECT EmployeeID, Quarter, QuarterlyAmount
FROM SalesTrend
WHERE QuarterlyAmount > PrevQuarter1 AND PrevQuarter1 > PrevQuarter2 AND PrevQuarter2 > PrevQuarter3;
โซ๏ธ List Customers Who Made Purchases in Each of the Last Three Years.
Schema: Orders (OrderID, CustomerID, OrderDate)
WITH YearlyOrders AS (
SELECT CustomerID,
EXTRACT(YEAR FROM OrderDate) AS OrderYear
FROM Orders
GROUP BY CustomerID, EXTRACT(YEAR FROM OrderDate)
),
RecentYears AS (
SELECT DISTINCT OrderYear
FROM Orders
WHERE OrderDate >= CURRENT_DATE - INTERVAL '3 years'
),
CustomerYearlyOrders AS (
SELECT CustomerID,
COUNT(DISTINCT OrderYear) AS YearCount
FROM YearlyOrders
WHERE OrderYear IN (SELECT OrderYear FROM RecentYears)
GROUP BY CustomerID
)
SELECT CustomerID
FROM CustomerYearlyOrders
WHERE YearCount = 3;
โซ๏ธ Find the Third Lowest Price for Each Product Category.
Schema: Products (ProductID, Name, CategoryID, Price)
WITH RankedPrices AS (
SELECT CategoryID,
Price,
DENSE_RANK() OVER (PARTITION BY CategoryID ORDER BY Price ASC) AS PriceRank
FROM Products
)
SELECT CategoryID, Price
FROM RankedPrices
WHERE PriceRank = 3;
โซ๏ธ Identify Products with Total Sales Exceeding a Specified Threshold Over the Last 30 Days.
Schema: Sales (SaleID, ProductID, SaleDate, Amount)
WITH RecentSales AS (
SELECT ProductID,
SUM(Amount) AS TotalSales
FROM Sales
WHERE SaleDate >= CURRENT_DATE - INTERVAL '30 days'
GROUP BY ProductID
)
SELECT ProductID, TotalSales
FROM RecentSales
WHERE TotalSales > 200;
Here you can find essential SQL Interview Resources๐
https://whatsapp.com/channel/0029VanC5rODzgT6TiTGoa1v
Like this post if you need more ๐โค๏ธ
Hope it helps :)
๐๐ข๐๐๐ข๐๐ฎ๐ฅ๐ญ๐ฒ - ๐๐๐๐ข๐ฎ๐ฆ
โซ๏ธDetermine the Top 5 Products with the Highest Revenue in Each Category.
Schema: Products (ProductID, Name, CategoryID), Sales (SaleID, ProductID, Amount)
WITH ProductRevenue AS (
SELECT p.ProductID,
p.Name,
p.CategoryID,
SUM(s.Amount) AS TotalRevenue,
RANK() OVER (PARTITION BY p.CategoryID ORDER BY SUM(s.Amount) DESC) AS RevenueRank
FROM Products p
JOIN Sales s ON p.ProductID = s.ProductID
GROUP BY p.ProductID, p.Name, p.CategoryID
)
SELECT ProductID, Name, CategoryID, TotalRevenue
FROM ProductRevenue
WHERE RevenueRank <= 5;
โซ๏ธ Identify Employees with Increasing Sales for Four Consecutive Quarters.
Schema: Sales (EmployeeID, SaleDate, Amount)
WITH QuarterlySales AS (
SELECT EmployeeID,
DATE_TRUNC('quarter', SaleDate) AS Quarter,
SUM(Amount) AS QuarterlyAmount
FROM Sales
GROUP BY EmployeeID, DATE_TRUNC('quarter', SaleDate)
),
SalesTrend AS (
SELECT EmployeeID,
Quarter,
QuarterlyAmount,
LAG(QuarterlyAmount, 1) OVER (PARTITION BY EmployeeID ORDER BY Quarter) AS PrevQuarter1,
LAG(QuarterlyAmount, 2) OVER (PARTITION BY EmployeeID ORDER BY Quarter) AS PrevQuarter2,
LAG(QuarterlyAmount, 3) OVER (PARTITION BY EmployeeID ORDER BY Quarter) AS PrevQuarter3
FROM QuarterlySales
)
SELECT EmployeeID, Quarter, QuarterlyAmount
FROM SalesTrend
WHERE QuarterlyAmount > PrevQuarter1 AND PrevQuarter1 > PrevQuarter2 AND PrevQuarter2 > PrevQuarter3;
โซ๏ธ List Customers Who Made Purchases in Each of the Last Three Years.
Schema: Orders (OrderID, CustomerID, OrderDate)
WITH YearlyOrders AS (
SELECT CustomerID,
EXTRACT(YEAR FROM OrderDate) AS OrderYear
FROM Orders
GROUP BY CustomerID, EXTRACT(YEAR FROM OrderDate)
),
RecentYears AS (
SELECT DISTINCT OrderYear
FROM Orders
WHERE OrderDate >= CURRENT_DATE - INTERVAL '3 years'
),
CustomerYearlyOrders AS (
SELECT CustomerID,
COUNT(DISTINCT OrderYear) AS YearCount
FROM YearlyOrders
WHERE OrderYear IN (SELECT OrderYear FROM RecentYears)
GROUP BY CustomerID
)
SELECT CustomerID
FROM CustomerYearlyOrders
WHERE YearCount = 3;
โซ๏ธ Find the Third Lowest Price for Each Product Category.
Schema: Products (ProductID, Name, CategoryID, Price)
WITH RankedPrices AS (
SELECT CategoryID,
Price,
DENSE_RANK() OVER (PARTITION BY CategoryID ORDER BY Price ASC) AS PriceRank
FROM Products
)
SELECT CategoryID, Price
FROM RankedPrices
WHERE PriceRank = 3;
โซ๏ธ Identify Products with Total Sales Exceeding a Specified Threshold Over the Last 30 Days.
Schema: Sales (SaleID, ProductID, SaleDate, Amount)
WITH RecentSales AS (
SELECT ProductID,
SUM(Amount) AS TotalSales
FROM Sales
WHERE SaleDate >= CURRENT_DATE - INTERVAL '30 days'
GROUP BY ProductID
)
SELECT ProductID, TotalSales
FROM RecentSales
WHERE TotalSales > 200;
Here you can find essential SQL Interview Resources๐
https://whatsapp.com/channel/0029VanC5rODzgT6TiTGoa1v
Like this post if you need more ๐โค๏ธ
Hope it helps :)
Prepare for GATE: The Right Time is NOW!
GeeksforGeeks brings you everything you need to crack GATE 2026 โ 900+ live hours, 300+ recorded sessions, and expert mentorship to keep you on track.
Whatโs inside?
โ Live & recorded classes with Indiaโs top educators
โ 200+ mock tests to track your progress
โ Study materials - PYQs, workbooks, formula book & more
โ 1:1 mentorship & AI doubt resolution for instant support
โ Interview prep for IITs & PSUs to help you land opportunities
Learn from Experts Like:
Satish Kumar Yadav โ Trained 20K+ students
Dr. Khaleel โ Ph.D. in CS, 29+ years of experience
Chandan Jha โ Ex-ISRO, AIR 23 in GATE
Vijay Kumar Agarwal โ M.Tech (NIT), 13+ years of experience
Sakshi Singhal โ IIT Roorkee, AIR 56 CSIR-NET
Shailendra Singh โ GATE 99.24 percentile
Devasane Mallesham โ IIT Bombay, 13+ years of experience
Use code UPSKILL30 to get an extra 30% OFF (Limited time only)
๐ Enroll for a free counseling session now: https://gfgcdn.com/tu/UI2/
GeeksforGeeks brings you everything you need to crack GATE 2026 โ 900+ live hours, 300+ recorded sessions, and expert mentorship to keep you on track.
Whatโs inside?
โ Live & recorded classes with Indiaโs top educators
โ 200+ mock tests to track your progress
โ Study materials - PYQs, workbooks, formula book & more
โ 1:1 mentorship & AI doubt resolution for instant support
โ Interview prep for IITs & PSUs to help you land opportunities
Learn from Experts Like:
Satish Kumar Yadav โ Trained 20K+ students
Dr. Khaleel โ Ph.D. in CS, 29+ years of experience
Chandan Jha โ Ex-ISRO, AIR 23 in GATE
Vijay Kumar Agarwal โ M.Tech (NIT), 13+ years of experience
Sakshi Singhal โ IIT Roorkee, AIR 56 CSIR-NET
Shailendra Singh โ GATE 99.24 percentile
Devasane Mallesham โ IIT Bombay, 13+ years of experience
Use code UPSKILL30 to get an extra 30% OFF (Limited time only)
๐ Enroll for a free counseling session now: https://gfgcdn.com/tu/UI2/
Important Data Engineering Concepts for Interviews
1. ETL Processes: Understand the ETL (Extract, Transform, Load) process, including how to design and implement efficient pipelines to move data from various sources to a data warehouse or data lake. Familiarize yourself with tools like Apache NiFi, Talend, and AWS Glue.
2. Data Warehousing: Know the fundamentals of data warehousing, including the star schema, snowflake schema, and how to design a data warehouse that supports efficient querying and reporting. Learn about popular data warehousing solutions like Amazon Redshift, Google BigQuery, and Snowflake.
3. Data Modeling: Master data modeling concepts, including normalization and denormalization, to design databases that are optimized for both read and write operations. Understand entity-relationship (ER) diagrams and how to use them to model data relationships.
4. Big Data Technologies: Gain expertise in big data frameworks like Apache Hadoop and Apache Spark for processing large datasets. Understand the roles of HDFS, MapReduce, Hive, and Pig in the Hadoop ecosystem, and how Sparkโs in-memory processing can accelerate data processing.
5. Data Lakes: Learn about data lakes as a storage solution for raw, unstructured, and semi-structured data. Understand the key differences between data lakes and data warehouses, and how to use tools like Apache Hudi and Delta Lake to manage data lakes efficiently.
6. SQL and NoSQL Databases: Be proficient in SQL for querying and managing relational databases like MySQL, PostgreSQL, and Oracle. Also, understand when and how to use NoSQL databases like MongoDB, Cassandra, and DynamoDB for storing and querying unstructured or semi-structured data.
7. Data Pipelines: Learn how to design, build, and manage data pipelines that automate the flow of data from source systems to target destinations. Familiarize yourself with orchestration tools like Apache Airflow, Luigi, and Prefect for managing complex workflows.
8. APIs and Data Integration: Understand how to integrate data from various APIs and third-party services into your data pipelines. Learn about RESTful APIs, GraphQL, and how to handle data ingestion from external sources securely and efficiently.
9. Data Streaming: Gain knowledge of real-time data processing using streaming technologies like Apache Kafka, Apache Flink, and Amazon Kinesis. Learn how to build systems that can process and analyze data in real time as it flows through the system.
10. Cloud Platforms: Get familiar with cloud-based data engineering services offered by AWS, Azure, and Google Cloud. Understand how to use services like AWS S3, Azure Data Lake, Google Cloud Storage, AWS Redshift, and BigQuery for data storage, processing, and analysis.
11. Data Governance and Security: Learn best practices for data governance, including how to implement data quality checks, lineage tracking, and metadata management. Understand data security concepts like encryption, access control, and GDPR compliance to protect sensitive data.
12. Automation and Scripting: Be proficient in scripting languages like Python, Bash, or PowerShell to automate repetitive tasks, manage data pipelines, and perform ad-hoc data processing.
13. Data Versioning and Lineage: Understand the importance of data versioning and lineage for tracking changes to data over time. Learn how to use tools like Apache Atlas or DataHub for managing metadata and ensuring traceability in your data pipelines.
14. Containerization and Orchestration: Learn how to deploy and manage data engineering workloads using containerization tools like Docker and orchestration platforms like Kubernetes. Understand the benefits of using containers for scaling and maintaining consistency across environments.
15. Monitoring and Logging: Implement logging for data pipelines to ensure they run smoothly and efficiently. Familiarize yourself with tools like Prometheus, Grafana, etc. for real-time monitoring and troubleshooting.
1. ETL Processes: Understand the ETL (Extract, Transform, Load) process, including how to design and implement efficient pipelines to move data from various sources to a data warehouse or data lake. Familiarize yourself with tools like Apache NiFi, Talend, and AWS Glue.
2. Data Warehousing: Know the fundamentals of data warehousing, including the star schema, snowflake schema, and how to design a data warehouse that supports efficient querying and reporting. Learn about popular data warehousing solutions like Amazon Redshift, Google BigQuery, and Snowflake.
3. Data Modeling: Master data modeling concepts, including normalization and denormalization, to design databases that are optimized for both read and write operations. Understand entity-relationship (ER) diagrams and how to use them to model data relationships.
4. Big Data Technologies: Gain expertise in big data frameworks like Apache Hadoop and Apache Spark for processing large datasets. Understand the roles of HDFS, MapReduce, Hive, and Pig in the Hadoop ecosystem, and how Sparkโs in-memory processing can accelerate data processing.
5. Data Lakes: Learn about data lakes as a storage solution for raw, unstructured, and semi-structured data. Understand the key differences between data lakes and data warehouses, and how to use tools like Apache Hudi and Delta Lake to manage data lakes efficiently.
6. SQL and NoSQL Databases: Be proficient in SQL for querying and managing relational databases like MySQL, PostgreSQL, and Oracle. Also, understand when and how to use NoSQL databases like MongoDB, Cassandra, and DynamoDB for storing and querying unstructured or semi-structured data.
7. Data Pipelines: Learn how to design, build, and manage data pipelines that automate the flow of data from source systems to target destinations. Familiarize yourself with orchestration tools like Apache Airflow, Luigi, and Prefect for managing complex workflows.
8. APIs and Data Integration: Understand how to integrate data from various APIs and third-party services into your data pipelines. Learn about RESTful APIs, GraphQL, and how to handle data ingestion from external sources securely and efficiently.
9. Data Streaming: Gain knowledge of real-time data processing using streaming technologies like Apache Kafka, Apache Flink, and Amazon Kinesis. Learn how to build systems that can process and analyze data in real time as it flows through the system.
10. Cloud Platforms: Get familiar with cloud-based data engineering services offered by AWS, Azure, and Google Cloud. Understand how to use services like AWS S3, Azure Data Lake, Google Cloud Storage, AWS Redshift, and BigQuery for data storage, processing, and analysis.
11. Data Governance and Security: Learn best practices for data governance, including how to implement data quality checks, lineage tracking, and metadata management. Understand data security concepts like encryption, access control, and GDPR compliance to protect sensitive data.
12. Automation and Scripting: Be proficient in scripting languages like Python, Bash, or PowerShell to automate repetitive tasks, manage data pipelines, and perform ad-hoc data processing.
13. Data Versioning and Lineage: Understand the importance of data versioning and lineage for tracking changes to data over time. Learn how to use tools like Apache Atlas or DataHub for managing metadata and ensuring traceability in your data pipelines.
14. Containerization and Orchestration: Learn how to deploy and manage data engineering workloads using containerization tools like Docker and orchestration platforms like Kubernetes. Understand the benefits of using containers for scaling and maintaining consistency across environments.
15. Monitoring and Logging: Implement logging for data pipelines to ensure they run smoothly and efficiently. Familiarize yourself with tools like Prometheus, Grafana, etc. for real-time monitoring and troubleshooting.
๐3โค1
Pyspark Interview Questions!!
Interviewer: "How would you remove duplicates from a large dataset in PySpark?"
Candidate: "To remove duplicates from a large dataset in PySpark, I would follow these steps:
Step 1: Load the dataset into a DataFrame
Step 2: Check for duplicates
Step 3: Partition the data to optimize performance
Step 4: Remove duplicates using the
Step 5: Cache the resulting DataFrame to avoid recomputing
Step 6: Save the cleaned dataset
Interviewer: "That's correct! Can you explain why you partitioned the data in Step 3?"
Candidate: "Yes, partitioning the data helps to distribute the computation across multiple nodes, making the process more efficient and scalable."
Interviewer: "Great answer! Can you also explain why you cached the resulting DataFrame in Step 5?"
Candidate: "Caching the DataFrame avoids recomputing the entire dataset when saving the cleaned data, which can significantly improve performance."
Interviewer: "Excellent! You have demonstrated a clear understanding of optimizing duplicate removal in PySpark."
Interviewer: "How would you remove duplicates from a large dataset in PySpark?"
Candidate: "To remove duplicates from a large dataset in PySpark, I would follow these steps:
Step 1: Load the dataset into a DataFrame
df = spark.read.csv("path/to/data.csv", header=True, inferSchema=True)Step 2: Check for duplicates
duplicate_count = df.count() - df.dropDuplicates().count()
print(f"Number of duplicates: {duplicate_count}")
Step 3: Partition the data to optimize performance
df_repartitioned = df.repartition(100)Step 4: Remove duplicates using the
dropDuplicates() methoddf_no_duplicates = df_repartitioned.dropDuplicates()Step 5: Cache the resulting DataFrame to avoid recomputing
df_no_duplicates.cache()Step 6: Save the cleaned dataset
df_no_duplicates.write.csv("path/to/cleaned/data.csv", header=True)Interviewer: "That's correct! Can you explain why you partitioned the data in Step 3?"
Candidate: "Yes, partitioning the data helps to distribute the computation across multiple nodes, making the process more efficient and scalable."
Interviewer: "Great answer! Can you also explain why you cached the resulting DataFrame in Step 5?"
Candidate: "Caching the DataFrame avoids recomputing the entire dataset when saving the cleaned data, which can significantly improve performance."
Interviewer: "Excellent! You have demonstrated a clear understanding of optimizing duplicate removal in PySpark."
๐2
๐๐๐ ๐๐ฅ๐๐ ๐๐ฒ๐ฟ๐๐ถ๐ณ๐ถ๐ฐ๐ฎ๐๐ถ๐ผ๐ป ๐๐ผ๐๐ฟ๐๐ฒ๐ ๐
Top Free Courses You Can Take Today
1๏ธโฃ Data Science Fundamentals
2๏ธโฃ AI & Machine Learning
3๏ธโฃ Python for Data Science
4๏ธโฃ Cloud Computing & Big Data
๐๐ข๐ง๐ค ๐:-
https://pdlink.in/41Hy2hp
Enroll For FREE & Get Certified ๐
Top Free Courses You Can Take Today
1๏ธโฃ Data Science Fundamentals
2๏ธโฃ AI & Machine Learning
3๏ธโฃ Python for Data Science
4๏ธโฃ Cloud Computing & Big Data
๐๐ข๐ง๐ค ๐:-
https://pdlink.in/41Hy2hp
Enroll For FREE & Get Certified ๐
โค1
How to become a data analyst/engineer -
Practice these daily:
โก๏ธ SQL
โก๏ธ Excel
โก๏ธ Python
โก๏ธ Power BI
โก๏ธ ETL/ELT
โก๏ธ Power Query
โก๏ธ Data modelling
โก๏ธ Data warehouse
โก๏ธ Exception handling
โก๏ธ Logging + debugging
#DataEngineering
Practice these daily:
โก๏ธ SQL
โก๏ธ Excel
โก๏ธ Python
โก๏ธ Power BI
โก๏ธ ETL/ELT
โก๏ธ Power Query
โก๏ธ Data modelling
โก๏ธ Data warehouse
โก๏ธ Exception handling
โก๏ธ Logging + debugging
#DataEngineering
๐1
๐๐ฒ๐๐ ๐ฃ๐๐๐ต๐ผ๐ป ๐๐ฅ๐๐ ๐๐ฒ๐ฟ๐๐ถ๐ณ๐ถ๐ฐ๐ฎ๐๐ถ๐ผ๐ป ๐๐ผ๐๐ฟ๐๐ฒ๐๐
Python is one of the most in-demand programming languages, used in data science, AI, web development, and automation.
Having a recognized Python certification can set you apart in the job market.
๐๐ข๐ง๐ค ๐:-
https://pdlink.in/4c7hGDL
Enroll For FREE & Get Certified ๐
Python is one of the most in-demand programming languages, used in data science, AI, web development, and automation.
Having a recognized Python certification can set you apart in the job market.
๐๐ข๐ง๐ค ๐:-
https://pdlink.in/4c7hGDL
Enroll For FREE & Get Certified ๐
๐1
Pyspark interview questions for Data Engineer
1. How do you handle data transfer between PySpark and external systems? 2. How do you deal with missing or null values in PySpark DataFrames?
3. Are there any specific strategies or functions you prefer for handling missing data?
4. What is broadcasting, and how is it useful in PySpark?
5. What is Spark and why is it preferred over MapReduce?
6. How does Spark handle fault tolerance?
7. What is the significance of caching in Spark?
8. Explain the concept of broadcast variables in Spark
9. What is the role of Spark SQL in data processing?
10. How does Spark handle memory management?
11. Discuss the significance of partitioning in Spark.
12. Explain the difference between RDDs, DataFrames, and Datasets.
13. What are the different deployment modes available in Spark?
14. What is PySpark, and how does it differ from Python Pandas?
15. Explain the difference between RDD, DataFrame, and Dataset in PySpark. 16. How do you create a DataFrame in PySpark?
17. What is lazy evaluation in PySpark and why is it important?
18. How can you handle missing or null values in PySpark DataFrames?
19. What are transformations and actions in PySpark, and can you give examples of each?
20. How do you perform joins between two DataFrames in PySpark? What are the joins available in PySpark?
Here, you can find free Resources ๐
https://whatsapp.com/channel/0029VanC5rODzgT6TiTGoa1v
All the best ๐๐
1. How do you handle data transfer between PySpark and external systems? 2. How do you deal with missing or null values in PySpark DataFrames?
3. Are there any specific strategies or functions you prefer for handling missing data?
4. What is broadcasting, and how is it useful in PySpark?
5. What is Spark and why is it preferred over MapReduce?
6. How does Spark handle fault tolerance?
7. What is the significance of caching in Spark?
8. Explain the concept of broadcast variables in Spark
9. What is the role of Spark SQL in data processing?
10. How does Spark handle memory management?
11. Discuss the significance of partitioning in Spark.
12. Explain the difference between RDDs, DataFrames, and Datasets.
13. What are the different deployment modes available in Spark?
14. What is PySpark, and how does it differ from Python Pandas?
15. Explain the difference between RDD, DataFrame, and Dataset in PySpark. 16. How do you create a DataFrame in PySpark?
17. What is lazy evaluation in PySpark and why is it important?
18. How can you handle missing or null values in PySpark DataFrames?
19. What are transformations and actions in PySpark, and can you give examples of each?
20. How do you perform joins between two DataFrames in PySpark? What are the joins available in PySpark?
Here, you can find free Resources ๐
https://whatsapp.com/channel/0029VanC5rODzgT6TiTGoa1v
All the best ๐๐
๐4
๐ฑ ๐๐ฟ๐ฒ๐ฒ ๐๐ผ๐๐ฟ๐๐ฒ๐ ๐๐ผ ๐๐ถ๐ฐ๐ธ๐๐๐ฎ๐ฟ๐ ๐ฌ๐ผ๐๐ฟ ๐๐ฎ๐๐ฎ ๐๐ป๐ฎ๐น๐๐๐ถ๐ฐ๐ ๐๐ฎ๐ฟ๐ฒ๐ฒ๐ฟ ๐ถ๐ป ๐ฎ๐ฌ๐ฎ๐ฑ๐
Looking to break into data analytics but donโt know where to start?๐
๐ The demand for data professionals is skyrocketing in 2025, & ๐๐ผ๐ ๐ฑ๐ผ๐ปโ๐ ๐ป๐ฒ๐ฒ๐ฑ ๐ฎ ๐ฑ๐ฒ๐ด๐ฟ๐ฒ๐ฒ ๐๐ผ ๐ด๐ฒ๐ ๐๐๐ฎ๐ฟ๐๐ฒ๐ฑ!๐จ
๐๐ข๐ง๐ค๐:-
https://pdlink.in/4kLxe3N
๐ Start now and transform your career for FREE!
Looking to break into data analytics but donโt know where to start?๐
๐ The demand for data professionals is skyrocketing in 2025, & ๐๐ผ๐ ๐ฑ๐ผ๐ปโ๐ ๐ป๐ฒ๐ฒ๐ฑ ๐ฎ ๐ฑ๐ฒ๐ด๐ฟ๐ฒ๐ฒ ๐๐ผ ๐ด๐ฒ๐ ๐๐๐ฎ๐ฟ๐๐ฒ๐ฑ!๐จ
๐๐ข๐ง๐ค๐:-
https://pdlink.in/4kLxe3N
๐ Start now and transform your career for FREE!
๐1
Breaking in to data engineering can be 100% free and 100% project-based!
Here are the steps:
- find a REST API you like as a data source. Maybe stocks, sports games, Pokรฉmon, etc.
- learn Python to build a short script that reads that REST API and initially dumps to a CSV file
- get a Snowflake or BigQuery free trial account. Update the Python script to dump the data there
- build aggregations on top of the data in SQL using things like GROUP BY keyword
- set up an Astronomer account to build an Airflow pipeline to automate this data ingestion
- connect something like Tableau to your data warehouse and build a fancy chart that updates to show off your hard work!
Here, you can find Data Engineering Resources ๐
https://whatsapp.com/channel/0029VanC5rODzgT6TiTGoa1v
All the best ๐๐
Here are the steps:
- find a REST API you like as a data source. Maybe stocks, sports games, Pokรฉmon, etc.
- learn Python to build a short script that reads that REST API and initially dumps to a CSV file
- get a Snowflake or BigQuery free trial account. Update the Python script to dump the data there
- build aggregations on top of the data in SQL using things like GROUP BY keyword
- set up an Astronomer account to build an Airflow pipeline to automate this data ingestion
- connect something like Tableau to your data warehouse and build a fancy chart that updates to show off your hard work!
Here, you can find Data Engineering Resources ๐
https://whatsapp.com/channel/0029VanC5rODzgT6TiTGoa1v
All the best ๐๐
โค4๐1