Apache® Spark™ News

Introducing Stream-Stream Joins in Apache Spark 2.3

Since we introduced Structured Streaming in Apache Spark 2.0, it has supported joins (inner join and some type of outer joins) between a streaming and a static DataFrame/Dataset. With the release of Apache Spark 2.3.0, now available in Databricks Runtime 4.0 as part of Databricks Unified Analytics Platform, we now support stream-stream joins. In this post, we will explore a canonical case of how to use stream-stream joins, what challenges we resolved, and what type of workloads they enable. Let’s start with the canonical use case for stream-stream joins – ad monetization.