Configure Dagster asset graph partitions with dynamic partition definitions to handle an unknown or growing set of partition keys at runtime

Steps

1. Define a DynamicPartitionsDefinition with a name string; partition keys are not known at definition time and are managed at runtime via the Dagster instance
2. Use dagster_instance.add_dynamic_partitions(partitions_def_name, [key1, key2]) to register new partition keys, typically inside a sensor that discovers new entities (e.g., new customer IDs or new files)
3. In the asset decorated with @asset(partitions_def=dynamic_def), access the current partition key via context.partition_key to scope the computation
4. In a sensor, emit SensorResult with run_requests=[RunRequest(partition_key=key, ...)] for each new partition key discovered, and add the partition keys to the dynamic definition before emitting requests
5. Use context.instance.delete_dynamic_partition(partitions_def_name, key) to remove partition keys that no longer need materialization, such as deleted entities