ffinfo commented on a change in pull request #4396: [AIRFLOW-3585] - Add edges to database URL: https://github.com/apache/airflow/pull/4396#discussion_r257423430
########## File path: airflow/models/dag_edge.py ########## @@ -0,0 +1,60 @@ +# -*- coding: utf-8 -*- +# +# Licensed to the Apache Software Foundation (ASF) under one +# or more contributor license agreements. See the NOTICE file +# distributed with this work for additional information +# regarding copyright ownership. The ASF licenses this file +# to you under the Apache License, Version 2.0 (the +# "License"); you may not use this file except in compliance +# with the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, +# software distributed under the License is distributed on an +# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +# KIND, either express or implied. See the License for the +# specific language governing permissions and limitations +# under the License. + +from sqlalchemy import Column, String, Index, Integer + +from airflow.utils.db import create_session + +from airflow.models.base import Base + + +class DagEdge(Base): + """ + Dags can originate from different places (user repos, master repo, ...) + and also get executed in different places (different executors). This + object represents a version of a DAG and becomes a source of truth for + a BackfillJob execution. A pickle is a native python serialized object, + and in this case gets stored in the database for the duration of the job. + + The executors pick up the DagPickle id and read the dag definition from + the database. + """ + + __tablename__ = "dag_edge" + + dag_id = Column(String(250), primary_key=True) + graph_id = Column(Integer, primary_key=True) + from_task = Column(String(250), primary_key=True) + to_task = Column(String(250), primary_key=True) + + __table_args__ = (Index('idx_dag_edge', dag_id, graph_id, from_task, to_task, unique=True),) Review comment: I think this depends a bit on the database implementation. I do think that some databases makes the index specific for 4 columns and therefore not compatible for search just 2 columns, this problem depends on the order of the columns. I think is does not harm to keep 2 indexes next to each other. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
