uranusjr commented on a change in pull request #17552:
URL: https://github.com/apache/airflow/pull/17552#discussion_r689286094
##########
File path: docs/apache-airflow/concepts/dags.rst
##########
@@ -148,14 +148,24 @@ The ``schedule_interval`` argument takes any value that
is a valid `Crontab <htt
with DAG("my_daily_dag", schedule_interval="0 * * * *"):
...
-Every time you run a DAG, you are creating a new instance of that DAG which
Airflow calls a :doc:`DAG Run </dag-run>`. DAG Runs can run in parallel for the
same DAG, and each has a defined ``execution_date``, which identifies the
*logical* date and time it is running for - not the *actual* time when it was
started.
+.. tip::
+
+ For more information on ``schedule_interval`` values, see :doc:`DAG Run
</dag-run>`.
+
+ If ``schedule_interval`` is not enough to express the DAG's schedule, see
:doc:`Timetables </howto/timetable>`.
+
+Every time you run a DAG, you are creating a new instance of that DAG which
Airflow calls a :doc:`DAG Run </dag-run>`. DAG Runs can run in parallel for the
same DAG, and each has a defined data interval, which identifies the *logical*
date and time range it is running for - not the *actual* time when it was
started.
As an example of why this is useful, consider writing a DAG that processes a
daily set of experimental data. It's been rewritten, and you want to run it on
the previous 3 months of data - no problem, since Airflow can *backfill* the
DAG and run copies of it for every day in those previous 3 months, all at once.
-Those DAG Runs will all have been started on the same actual day, but their
``execution_date`` values will cover those last 3 months, and that's what all
the tasks, operators and sensors inside the DAG look at when they run.
+Those DAG Runs will all have been started on the same actual day, but their
data intervals will cover those last 3 months, and that's what all the tasks,
operators and sensors inside the DAG look at when they run.
Review comment:
Definitely clearer than the previous wording!
--
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.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
