Azure Stream Analytics Inputs

Azure Stream Analytics is a real time, big data, events processing and analytics engine. Stream Analytics jobs can accept multiple inputs and are highly integrated with other Azure services. Azure Stream Analytics natively supports inputs from Azure Event Hubs, Azure IoT hub and Azure Blob Storage.

Stream Analytics data inputs can be of two types:

Data Stream Inputs

As the name suggests, Data stream inputs are provided for ingesting streaming data such as social media feed, sensor data, web clickstream etc.  from a data streaming source. The supported data streaming sources are Azure Event Hubs, Azure IoT hub or Azure Blob Storage. Every Azure Stream analytics job must have at least one Data stream input.

Reference Data Inputs

The second type of input that Azure Stream Analytics supports is the reference data input. Reference data is the static or slowly changing data which are used for lookups and creating relationships. The reference data can be used to join with the streaming source data, which is like joining tables in a traditional SQL setup. The supported sources for Reference data input are Azure Blob Storage and Azure SQL Database. There is a size limitation of up to 300 MB on the reference data source. This size limitation can vary depending on query complexity and the allocated streaming units.

Reference: https://docs.microsoft.com/en-us/azure/stream-analytics/stream-analytics-add-inputs