mik-laj commented on pull request #9170: URL: https://github.com/apache/airflow/pull/9170#issuecomment-641653054
@ashb It looks good, but I don't know if it suits our code style. We use explicit joins instead of relying on ORM generated more often. Generating joints by ORM together with the use of multi-column primary keys can lead to spaghetti. Each model will have a relationship with each model because many values are repeated. We only use ORM-based relationships in one place - DagModel.tags It fits here because we can easily retrieve the object(DagModel) and metadata. (DagTag). In other places, we need careful control to ensure good performance. I also prepared an example. https://github.com/apache/airflow/pull/9170/commits/16f829927859604336013dd7a9755fcf7000f786 ```python query = session.query(XCom) query = query.filter(and_(XCom.dag_id == dag_id, XCom.task_id == task_id, XCom.key == xcom_key)) query = query.join(DR, and_(XCom.dag_id == DR.dag_id, XCom.execution_date == DR.execution_date)) query = query.filter(DR.run_id == dag_run_id) q_object = query.one_or_none() ``` ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
