Databricks 9.1.x-scala2.12 refers to the Databricks Runtime Version 9.1 LTS which includes Apache Spark 3.1.2 and Scala 2.12. This was a Long Term Support (LTS) version, meaning it received extended support and maintenance updates.

Key features of Databricks Runtime 9.1 LTS:

• Auto Loader schema hints: Improved functionality for inferring and evolving schemas for data ingestion.
• Avro file support for merge schema: Enhanced support for Avro files when merging schemas.
• Auto Loader incremental listing support: Optimized incremental listing of files for more efficient data ingestion.
• Improved error handling: Better error messages and handling in various components.
• Numerous library upgrades: Updated versions of various libraries and dependencies.