title: How to purge historical data when clearing a run from Airflow dashboard?
body: <p>Here is a typical request:</p>
  <p>I built a DAG which updates daily from 2020-01-01. It runs an <code>INSERT</code> SQL query using {execution_date} as a parameter. Now I need to update the query and rerun for the past 6 months.</p>
  <p>I found out that I have to pause Airflow process, <code>DELETE</code> historical data, <code>INSERT</code> manually and then re-activate Airflow process because Airflow catch-up does not remove historical data when I <strong>clear</strong> a run.</p>
  <p>I'm wondering if it's possible to script the <strong>clear</strong> part so that every time I click a run, clear it from UI, Airflow runs a clear script in the background?</p>