Interview Prep

Spark Configuration, Monitoring, and Tuning, covering theory + code examples Here’s a comprehensive guide to Spark Configuration, Monitoring, and Tuning, covering theory + code examples. It’s especially helpful for Data Engineers working on performance optimization or preparing for interviews. ⚙️ Spark Configuration, Monitoring, and Tuning 🔧 1. Understand Components of the Spark Cluster A Spark…

Question:-“What really happens inside the Spark engine when I run a simple .read() or .join() on a file?” Let me break this down in a clear, interview-ready, cluster-level Spark execution flow, step-by-step: 🔍 Spark Cluster Background Process (Example: spark.read.csv(…)) Imagine this code: Let’s analyze it in chronological order: ✅ 1. Driver Program Starts the Spark…

This is a fantastic deep-dive! Let’s answer your question clearly and technically: ✅ Question Recap: If I read a 1 GB CSV file or a 1 GB Hive table into a DataFrame —❓ Does defaultParallelism apply?❓ How are tasks created and executed in this case? 🔧 Short Answer: No, defaultParallelism does not directly control how…

Advanced-level PySpark, Big Data systems, and backend engineering—here’s a breakdown of what questions you can expect, based on industry trends. ✅ Topic-wise Breakdown of Likely Questions 🔹 PySpark & Big Data (Core Focus) Area Sample Questions PySpark DataFrame APIs – How is selectExpr different from select?- Use withColumn, explode, filter in one chain.- Convert nested…

Certainly! Here’s the complete crisp PySpark Interview Q&A Cheat Sheet with all your questions so far, formatted consistently for flashcards, Excel, or cheat sheet use: Question Answer How do you handle schema mismatch when reading multiple JSON/Parquet files with different structures? Use .option(“mergeSchema”, “true”) when reading Parquet files; for JSON, unify schemas by selecting common…

Explain a scenario on schema evolution in data pipelines Here’s an automated Python script using PySpark that performs schema evolution between two datasets (e.g., two Parquet files or DataFrames): ✅ Features: 🔧 Prerequisites: 🧠 Script: Schema Evolution Handler 🔍 Output: 💡 Notes: Automated script for schema evolution. first to check what fields are missing or…

Comparative overview of partitions, bucketing, segmentation, and broadcasting in PySpark, Spark SQL, and Hive QL in tabular form, along with examples Here’s a comparative overview of partitions, bucketing, segmentation, and broadcasting in PySpark, Spark SQL, and Hive QL in tabular form, along with examples: Concept PySpark Spark SQL Hive QL Partitions df.repartition(numPartitions, “column”) creates partitions based on specified column. CREATE TABLE table_name PARTITIONED BY (col1 STRING) allows data to be organized by partition. ALTER TABLE…