Due to expected difficulty in altering the revision table (see T161671: Compacting the revision table), the actor and comment migrations created tables named revision_comment_temp and revision_actor_temp to relate the rev_id and the comment_id/actor_id, with the plan being to eventually alter revision to contain rev_comment_id and rev_actor columns and drop those relation tables. This task tracks that "eventually".
- 0. Wait for the main actor and comment migration to be done (except for DBA work).
- 1. Alter revision to drop rev_comment, rev_user, and rev_user_text and add rev_comment_id and rev_actor. (T161671)
- 1.1. Write and merge the MediaWiki patch.
- 1.2. Have DBAs perform the change.
- 2. Introduce a migration from using revision_comment_temp and revision_actor_temp (old) to rev_comment_id and rev_actor (new).
- 2.1. Write and merge the MediaWiki patch, assuming it wasn't included in 1.1.
- 2.2. Check for extensions assuming the temp tables exist.
- 3. Set migration stage to write-both/read-old.
- 4. Run the maintenance script to backfill rev_comment_id and rev_actor.
- 5. Set migration stage to write-both/read-new.
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5.1. Announce changes to wikitech-l and cloud.not necessary, since the tables cannot be queried directly. - 5.2. Update WMCS views to read the new schema.
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- 6. Set migration stage to write-new/read-new.
- 7. Remove old tables and code.