RDDs — The Foundation
What an RDD really is, the five properties, transformations, actions, lineage, and why fault tolerance is essentially free.
Pass Week 1 to unlock this content.
Each week of the study path opens after you score 80% or higher on the previous week's quiz. This isn't to gatekeep — it's because the concepts in later weeks build directly on the ones before them, and the quiz is the cheapest way to find out whether the foundation is in place.
Go to Week 1What you'll cover in Week 2
Once unlocked, Week 2 runs roughly 80 minutes of reading paired with 5 interactive visualizations, followed by a 15-question self-check quiz. The reading is grounded in the official Apache Spark documentation — every claim cites the docs.
- What RDD stands for and why immutability matters
- The five internal properties of every RDD
- Creating RDDs: parallelize, textFile, transformations
- The reduceByKey vs groupByKey performance trap
- Lineage — Spark's memory of how an RDD was made
- Fault tolerance through recomputation
Why this week matters
By the end of Week 2 you'll be able to explain rdds — the foundationconfidently — not just describe it, but reason about edge cases, predict performance, and read a Spark UI for the concepts it touches. That's the bar this study path aims for: not memorization, but the kind of working understanding that lets you debug real jobs.