Databricks Runtime 9 refers to a set of software releases by Databricks for their data analytics platform. The most notable release in this series is Databricks Runtime 9.1 LTS (Long Term Support), which includes the following key features and improvements:

• Apache Spark 3.1.2: This version brings all the fixes and improvements from Spark 3.1.2, including enhanced performance, stability, and new features.
• Photon Public Preview: Photon is a high-performance query engine for Databricks, designed to accelerate data processing and analytics.
• Databricks Autologging (Public Preview): This feature automatically tracks machine learning experiments, capturing model parameters, metrics, files, and lineage information.
• Additional enhancements: Various bug fixes, library upgrades, and performance optimizations across different components of the Databricks Runtime.