Triggering a backfill

A daily pipeline called backfill_demo was paused for three days while a bug was fixed. Your manager asks you to backfill the missing dates so the reports are up to date.

Follow these steps:

1. In the Dags view, activate backfill_demo.
2. Click the trigger button and select Backfill (not "Single Run").
3. Set To to Today and From to a few days earlier, then click Run Backfill.
4. Open the Dag, go to the Runs tab, and watch the runs that appear.

You ran a backfill and watched the runs appear in the Runs tab. What decides how many Dag runs a backfill creates?