# TimelineActivity migration to morph - Creates `timelineActivities2` relations on Company, Dashboard, Note, Opportunity, Person, Task, Workflow, WorkflowRun, and WorkflowVersion entities with proper metadata and cascade delete behavior. It was required to create standard fields as well since the mapObjectMetadataByUniqueIdentifier needs it. otherwise the fields won't be considered - Feature Flag `IS_TIMELINE_ACTIVITY_MIGRATED` necessary to have the two states in parallel. It is used as a stamp once the migration has been run - Migration is done using the coreDataSource. Why ? even though is unsafe to use, the first implementation of the migration took forever on each workspace. See [this commit](https://github.com/twentyhq/twenty/pull/15652/commits/477011e8d7d4c580f79ba7ec4a8fb002a3ec86b2) The plan for this complex migration is as follows :  Note: we will need to rename fields in the release 1.12 (there is no easy way to do all this in one release)