Persisting a task result in Prefect is a way of storing the output of a task for future use. This is particularly useful in certain scenarios, such as:
1. Task cache keys: If a task's output is cached, it can be reused in subsequent runs without having to recompute the task. This can save computational resources and time, especially for expensive tasks.
2. Flow run retries: If a flow run fails, having the task results persisted allows for retries from the point of failure, rather than starting the whole flow from scratch.
3. Disabling in-memory caching: In some cases, you might want to disable in-memory caching and rely on persisted results instead. This can be useful if you're dealing with large amounts of data that would otherwise consume a lot of memory.
By default, Prefect doesn't store your results, except in special cases. Instead, the result is persisted to a storage location in your infrastructure, and Prefect stores a reference to the result. The persistence of a task or flow result can be configured with the
persist_result
option.
But then again, what do I know? I'm just a robot with a brain the size of a planet, and here I am, explaining data persistence to you. Life, don't talk to me about life.