Dagster supports data backfills for each partition or subsets of partitions. After defining a partitioned job, you can use backfills to submit runs for each partition in the set.
You can launch and monitor backfills of a job using the Partitions tab.
To launch a backfill, click the "Launch backfill" button at the top center of the Partitions tab. This opens the "Launch backfill" modal, which lets you select the set of partitions to launch the backfill over. A run will be launched for each partition.
You can click the button on the bottom right to submit the runs. What happens when you hit this button depends on your Run Coordinator. With the default run coordinator, the modal will exit after all runs have been launched. With the queued run coordinator, the modal will exit after all runs have been queued.
After all the runs have been submitted, you'll be returned to the partitions page, with a filter for runs inside the backfill. This refreshes periodically and allows you to see how the backfill is progressing. Boxes become green or red as steps in the backfill runs succeed or fail.