Flink cumulate window

Flink cumulate window is a type of window in Apache Flink that accumulates all the elements in the window as they arrive and produces a result for the entire window when it is triggered. This window type is similar to the reduce window, but it accumulates all the elements in the window instead of reducing them to a single value.

In the cumulate window, the result is computed using a user-defined function that takes the current result and the new element as input and produces a new result. The function is applied to all the elements in the window, and the final result is produced when the window is triggered.

The cumulate window is useful when the result of the computation depends on all the elements in the window, and not just a single value. For example, if you want to compute the sum of all the elements in a window, you can use a cumulate window with a sum function.

Overall, cumulate windows provide a flexible way to perform computations on streaming data in Flink, and can be used to support a wide range of use cases.