Greg H
02/16/2024, 10:20 AMScout
02/16/2024, 10:20 AMeager
, which means that any downstream assets will be refreshed anytime the source data asset is updated. This allows you to only define a job to refresh your source tables/assets, and the rest of the assets will be automatically built when the source asset changes, adhering to the policies you've set. The documentation also mentions that AMPs can be declared on an asset-by-asset basis and can be applied to multiple assets at once. This means you can have fine-grained control over how and when each asset is materialized in response to changes in their dependencies. Remember that AMPs are an experimental feature, and you should refer to the [Auto-materializing Assets documentation](https://docs.dagster.io/concepts/assets/asset-auto-execution) for more details on how to implement them in your pipelines.Greg H
02/20/2024, 4:33 PMScout
02/20/2024, 4:33 PMAutoMaterializePolicy
class from the dagster
module. 3. Define the Policy: Create an instance of AutoMaterializePolicy
using one of the prebuilt policies like eager
or lazy
, or customize it by adding or removing rules. 4. Apply the Policy to Assets: Assign the policy to your assets using the auto_materialize_policy
argument in the asset definition. Here's an example of how you might define and apply an eager auto-materialization policy to an asset: python from dagster import asset, AutoMaterializePolicy # Define an eager auto-materialization policy eager_policy = AutoMaterializePolicy.eager() @asset(auto_materialize_policy=eager_policy) def my_asset(): # Asset computation logic here ...
In this example, my_asset
will be automatically materialized whenever its upstream dependencies are updated, because the eager
policy includes rules that trigger materialization when parent assets are updated. If you want to customize the policy further, you can add or remove rules using the with_rules
or without_rules
methods: python from dagster import AutoMaterializePolicy, AutoMaterializeRule # Customize the policy by removing a specific rule custom_policy = AutoMaterializePolicy.eager().without_rules( AutoMaterializeRule.skip_on_parent_missing(), ) @asset(auto_materialize_policy=custom_policy) def my_custom_asset(): # Asset computation logic here ...
In this customized policy, my_custom_asset
will still be materialized eagerly, but it won't skip materialization if a parent asset is missing. Please note that the API for defining auto-materialization policies is subject to change, as it is an experimental feature. Always refer to the latest [Dagster documentation](https://docs.dagster.io/_apidocs/assets) for the most up-to-date guidance on using auto-materialization policies.Greg H
02/21/2024, 9:39 PMScout
02/21/2024, 9:39 PM@dbt_assets
decorator provided by the dagster-dbt
integration to load your dbt models as Dagster assets. To ensure that downstream dbt models are automatically built when you refresh the source data, you can apply an auto-materialization policy to these dbt assets. Here's a general outline of how you might set this up: 1. Load dbt Models as Assets: Use the @dbt_assets
decorator to load your dbt models into Dagster as assets. 2. Define Auto-Materialization Policy: Define an auto-materialization policy that suits your needs (e.g., eager
to automatically materialize downstream assets when the source changes). 3. Apply the Policy to dbt Assets: Apply the auto-materialization policy to your dbt assets. Here's an example of how this might look in code: python from dagster_dbt import dbt_assets from dagster import AutoMaterializePolicy # Define an eager auto-materialization policy eager_policy = AutoMaterializePolicy.eager() # Load dbt models as assets and apply the auto-materialization policy @dbt_assets(auto_materialize_policy=eager_policy) def my_dbt_assets(context, dbt): # This function should invoke dbt commands to run your dbt project # For example, you might run 'dbt run' to materialize your dbt models result = dbt.run() yield from result
In this example, my_dbt_assets
represents your dbt models loaded as Dagster assets, and they are configured to be materialized eagerly based on the defined policy. When you run a job that refreshes the source data, Dagster will automatically trigger the materialization of downstream dbt models that depend on those sources, according to the rules defined in the eager_policy
. Please note that the actual implementation may vary based on your specific dbt project setup and the version of Dagster and dagster-dbt you are using. Always refer to the latest [dagster-dbt documentation](https://docs.dagster.io/_apidocs/libraries/dagster-dbt) for detailed instructions and examples on how to integrate dbt with Dagster, including the use of auto-materialization policies with dbt assets.Greg H
02/21/2024, 9:50 PMScout
02/21/2024, 9:50 PMrun-operation
to trigger external processes.
Here's a simplified example of how you might define these stages in Dagster:
```python
from dagster import job, op
from dagster_dbt import dbt_cli_resource
@op(required_resource_keys={"dbt"})
def stage_models(context):
context.resources.dbt.run(models=["+tag:staging"])
@op(required_resource_keys={"dbt"})
def transform_models(context):
context.resources.dbt.run(models=["+tag:transforming"])
@op(required_resource_keys={"dbt"})
def mart_models(context):
context.resources.dbt.run(models=["+tag:marts"])
@op
def transfer_to_service():
# Logic to transfer data to another service
...
@job(resource_defs={"dbt": dbt_cli_resourceScout
02/21/2024, 9:51 PMop
represents a stage in the dbt project, and the my_dbt_pipeline
job defines the order in which these stages should be executed. The start_after
argument is used to specify dependencies between stages. Remember to tailor the structure to your specific needs and consider the complexity of your transformations, the frequency of data updates, and the requirements of the downstream service that consumes your data marts. Always refer to the latest Dagster and dbt documentation for best practices and detailed guidance on structuring your data pipelines.