Simple Queries in Spark Catalyst Optimisation (2) Join and Aggregation
Original URL: https://medium.com/@wx.london.cun/simple-queries-in-spark-catalyst-optimisation-2-join-and-aggregation-c03f07a1dda8
Article Written: December 5, 2016
Added: November 23, 2025
Type: tech2
Summary
This article explores the join and aggregation operations in Spark's Catalyst optimization engine. It discusses how Spark generates execution plans for these operations, including SortMergeJoin and HashAggregate, and the underlying mechanisms that ensure efficient data processing. The author highlights the complexities of data shuffling and the importance of distribution and ordering in Spark plans. Overall, the article provides insights into the optimization strategies employed by Spark Catalyst for handling join and aggregation queries.