Batch archival

EditGroups stores a copy of the edit metadata, for each edit tracked by the tool. As times goes by, this means maintaining a fairly large database, with an edit table with hundreds of millions of rows.

Since the purpose of EditGroups is primarily to provide a view on batches (rather than individual edits), we do not actually need to store all these edits for ever. Once a batch is old enough, the chances that anyone will want to undo it are low (since its changes will be burried deep in the history and many will not be allowed to be undone by Wikibase).

Batch archival consists in deleting edits from the database for old batches. This is configurable using the following settings:

• BATCH_ARCHIVAL_DELAY: amount of time after which batches should be archived (one year by default);

• EDITS_KEPT_AFTER_ARCHIVAL: number of edits to keep in each archived batch. This is intended to help get a sense of what the batch does even after archival (10 by default);

• BATCH_ARCHIVAL_PERIODICITY: how often should we check for old batches and archive them (daily by default).

Once a batch is archived, it can no longer be undone.

Disabling archival

If EditGroups is running on a small Wikibase instance, or if storing most edits from Wikibase in EditGroups’ database is not a concern, you can disable archival by removing the archive_batches task from the CeleryBeat schedule in editgroups/settings/common.py.