olehborysevych commented on code in PR #29507: URL: https://github.com/apache/beam/pull/29507#discussion_r1411123336
########## learning/prompts/documentation-lookup/11_basic_state.md: ########## @@ -0,0 +1,20 @@ +Prompt: +What is a State in Apache Beam? +Response: +[State](https://beam.apache.org/documentation/basics/#state-and-timers) in Apache Beam is an API that allows for managing per-key state in element-wise operations like [ParDo](https://beam.apache.org/documentation/programming-guide/#pardo) or Map. It enables fine-grained control over aggregations, particularly in situations where [windowing](https://beam.apache.org/documentation/programming-guide/#windowing) and [triggers](https://beam.apache.org/documentation/programming-guide/#triggers) are insufficient. + +State is [scoped](https://beam.apache.org/documentation/programming-guide/#state-and-timers) to the current processing key within a window, meaning each key has its own state. It's particularly useful for complex aggregations across multiple elements. + +Beam provides several [types of state](https://beam.apache.org/documentation/programming-guide/#types-of-state) that can be used for different use cases including scalar and collection values: +- ValueState +- BagState +- SetState +- MapState +- OrderedListState +- CombiningState + +Per-key state needs to be garbage collected, or eventually the increasing size of state may negatively impact performance. See [here](https://beam.apache.org/documentation/programming-guide/#garbage-collecting-state) for more info on common strategies for garbage collecting state. + +See community blogpost on [Stateful Processing](https://beam.apache.org/blog/stateful-processing/) for more information. Review Comment: Done -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
