Data Engineer II Interview Questions and Answers

Key concepts in joining tables using PySpark

• Understanding the different types of joins: inner join, outer join, left join, right join

• Specifying the join condition using 'on' or 'using' clauses

• Handling duplicate column names after joining by aliasing or dropping columns

• Utilizing broadcast joins for small tables to improve performance

HDFS stands for Hadoop Distributed File System, a distributed file system designed to store and manage large amounts of data across multiple machines.

• HDFS is part of the Apache Hadoop project

• It is designed to be highly fault-tolerant and scalable

• Data is stored in blocks across multiple nodes in a cluster

• HDFS is commonly used for big data processing and analytics