> For the complete documentation index, see [llms.txt](https://docs.feast.dev/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.feast.dev/master/getting-started/concepts/stream-feature-view.md). # Stream feature view `StreamFeatureView` is a type of feature view in Feast that allows you to define features that are continuously updated from a streaming source. It is designed to handle real-time data ingestion and feature generation, making it suitable for use cases where features need to be updated frequently as new data arrives. ### Supported Compute Engines * [x] LocalComputeEngine * [x] SparkComputeEngine * [ ] FlinkComputeEngine ### Key Capabilities * **Real-time Feature Generation**: Supports defining features that are continuously updated from a streaming source. * **Transformations**: Apply transformation logic (e.g., `feature_transformation` or `udf`) to raw data source. * **Aggregations**: Define time-windowed aggregations (e.g., `sum`, `avg`) over event-timestamped data. * **⚡ Tiling with Intermediate Representations**: Enable efficient pre-aggregation with correct merging semantics for holistic aggregations like `avg` and `std`. This provides faster queries while maintaining mathematical accuracy. [Learn more about tiling](/master/getting-started/concepts/tiling.md) * **Feature resolution & execution**: Automatically resolves and executes dependent views during materialization or retrieval. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.feast.dev/master/getting-started/concepts/stream-feature-view.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.