The CampaignEvents extension now uses a separate table (ce_tracking_tools, see T334143) to store tracking tools. As part of the migration (T336364), we need to drop the old columns. Note that these columns are not used yet, so they should only contain NULL values and can be dropped safely.

ALTERs to run:

ALTER TABLE campaign_events DROP COLUMN event_tracking_tool_id, DROP COLUMN event_tracking_tool_event_id;

1. Where to run those changes: The table is in the extension1 cluster. There, it can be found in the per-wiki databases of testwiki, test2wiki, and officewiki, as well as in the wikishared database. So it's a total of 4 places.
2. When to run those changes: After deployment of 1.41.0-wmf.12, next week
3. If the schema change is backwards compatible: Yes
4. If the schema change has been tested already on some of the test/beta wikis: Tested locally and in beta (T336362)
5. if the data should be made available on the labs replicas and/or dumps: while we don't replicate data from x1, these columns are currently configured as public. Said configuration should be removed from https://gerrit.wikimedia.org/g/operations/puppet/+/2bf88ad0f7c6e1c54fd278c9568b55cd2e3c69f9/modules/role/files/mariadb/filtered_tables.txt#198

Progress:

• testwiki (x1)
• test2wiki (x1)
• officewiki (x1)
• wikishared (x1)