# ask-ai

Andy Smith

03/04/2024, 11:29 PM
If I have a downstream asset that auto materialises when an upstream asset changes, does dagster prevent the upstream asset rematerializing whilst the downstream asset is materialising?


03/04/2024, 11:29 PM
The documentation does not explicitly state that Dagster prevents an upstream asset from rematerializing while a downstream asset is materializing due to an auto-materialization policy. However, Dagster's auto-materialization policies are designed to trigger the materialization of downstream assets when their upstream dependencies have changed. In a scenario where an upstream asset changes and triggers the auto-materialization of a downstream asset, the expectation is that the upstream asset's change has already been materialized, which then leads to the downstream asset's materialization. The auto-materialization policy does not inherently lock or prevent changes to the upstream asset during the downstream asset's materialization process. If there are concerns about concurrent materializations and dependencies, it may be necessary to implement additional logic or use other features of Dagster to manage the execution order or to ensure that the materializations do not interfere with each other. For example, you could use sensors or schedules to control the timing of materializations more granularly. For specific use cases or more complex dependency management, it's recommended to refer to the latest Dagster documentation or seek advice from the Dagster community for the most appropriate solution. Is there a way to ignore updates for par... button Ensure that upstream assets are material... button [auto-materialize] How to only auto-mate... button Automating your data pipelines | Dagster... button Thank you for your feedback!