Since we decided to remove support for the Drupal 7 to Drupal 8 upgrade path, update hooks are no longer being added consistently and it no longer makes sense to add update hooks that will never be run. This document should be used to document things that would have required update hooks and may now need data migrations.
See https://drupal.org/node/2168011 for more information.
Variables to state or config
(list issues here with a brief note)
Added or removed database fields and tables
Not all schema changes require data migration.
Migration needed
(list issues here with a brief note)
file_managed.timestamp has been renamed to changed. https://drupal.org/node/2074475
No migration needed
https://drupal.org/node/2149841: Create UUIDs and add them to the aggregator_feed table.
Content entity conversions
UUIDs for content entities (no migration needed)
Numerous existing update hooks add UUIDs to existing content entities. With migrate, the UUIDs will be automatically generated when the new entity is created during migration, so these updates just need to be double-checked to verify they are working as intended.
https://drupal.org/node/2149841: Create UUIDs and add them to the aggregator_feed table.