Description: The ‘Side Input’ in Google Dataflow refers to an additional input that can be provided to a transformation, which is not part of the main input of the data flow. This feature allows for enriching data processing by incorporating additional information that may be relevant to the ongoing transformation. Side inputs are particularly useful in situations where data from different sources needs to be combined or when conditional logic based on external information is required. By using side inputs, developers can create more complex and flexible workflows, thus optimizing data analysis and manipulation. This functionality integrates smoothly into the Dataflow programming model, allowing users to define how and when these additional inputs should be used in their transformations, resulting in more efficient and effective data processing.
Uses: Side inputs are primarily used in real-time and batch data processing, where there is a need to combine data from different sources. For example, they can be used to provide configurations, parameters, or reference data that do not change frequently, allowing transformations to be performed more efficiently. They are also useful in analysis scenarios where conditional logic based on external data is needed, such as validation lists or alert thresholds.
Examples: A practical example of a side input could be a workflow processing financial transactions, where a side input is used to access a list of VIP customers that require special handling. Another example would be a recommendation system that uses side inputs to access product data not included in the main data flow, thus allowing for personalized recommendations.
