Home › Interview Questions › What is the default size threshold for broadcastin…

What is the default size threshold for broadcasting a table in Spark?

🟢 Easy Conceptual Fresher level
1Times asked
Sep 2026Last seen
Sep 2026First seen

💡 Model Answer

In Spark, the default threshold for automatically broadcasting a table is 10 megabytes. This value is controlled by the configuration property spark.sql.autoBroadcastJoinThreshold. If a table’s size is below this threshold, Spark will broadcast it to all executors during a join, eliminating the need for a shuffle. The threshold can be increased or decreased by setting the property to a larger or smaller value, or set to a negative number to disable automatic broadcasting entirely. For example, spark.conf.set("spark.sql.autoBroadcastJoinThreshold", "20MB") will allow tables up to 20 MB to be broadcasted.

This answer was generated by AI for study purposes. Use it as a starting point — personalize it with your own experience.

🎤 Get questions like this answered in real-time

Assisting AI listens to your interview, captures questions live, and gives you instant AI-powered answers on a discreet on-screen overlay.

Get Assisting AI — Starts at ₹500