Reference data is a dataset that is static or slow changing in nature which you can correlate with real-time data streams to augment the data. Azure Stream Analytics leverages versioning of reference data to augment streaming data by the reference data that was valid at the time the event was generated. One of the most... Read more

https://blogs.msdn.microsoft.com/sqlserverstorageengine/2019/02/04/azure-stream-analytics-now-supports-azure-sql-database-as-reference-data-input/