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Spark: Key Topics for Data Engineering Interviews Part - 1
Key Topics for Data Engineering Interviews
6 min readApr 22, 2025
Introduction
Spark has become the de facto standard for big data processing, and acing an Apache Spark interview requires a solid understanding of its core concepts.
In this blog series, I will dive deep into the most frequently asked Spark interview questions, complete with practical use cases, efficiency comparisons, and syntax examples.
Lets get started —
1️⃣ Repartition vs. Coalesce
Repartition:
- Functionality: Increases or decreases the number of partitions by reshuffling the data.
- When to Use: When you need even distribution across partitions.
- Syntax:
rdd = rdd.repartition(10)
Coalesce:
- Functionality: Reduces the number of partitions without full shuffle.
- When to Use: When reducing partitions with minimal shuffle.
- Syntax:
rdd = rdd.coalesce(2)
2️⃣ SortBy vs. OrderBy
SortBy:
- Functionality: Sorts data within each partition…