Rails adds config rake_eager_loadRails has added the option to eager load all the registered name spaces in rake tasks.
Rails has added support for automatic database connection switching from primary to the replicaRails has added support for automatic database connection switching from primary to the replica
Rails 6.1 adds at option to perform_enqueued_jobs test helperRails 6.1 has added at option to perform_enqueued_jobs test helper to run only jobs which are scheduled at or before the passed in time
Rails adds ActiveRecord API for switching multiple database connectionsRails adds ActiveRecord API connects_to and connected_to for switching connections to support multiple databases.
Rails introduces disallowed deprecations in ActiveSupportRails has added support to configure disallowed deprecations.
Rails has added a benchmark generatorRails has added a benchmark generator for scripts to benchmark Rails application.
Rails adds support for if_exists/if_not_exists on remove_column/add_column in migrationsRails adds support for if_exists/if_not_exists on remove_column/add_column in migrations to silently ignore migrations
Rails 6 adds rails db:system:change commandRails 6 adds rails db:system:change command to allow switching database configuration
Rails 6 - ActiveSupport Deprecations in Unicode and Chars support in favour of StringRails 6 has deprecated methods in Unicode and Chars support for ActiveSupport in favor of using ruby 2.3+ String methods directly.
Rails 6.1 adds support for multiple storage services to Active StorageRails 6.1 adds support to configure storage services for individual attachment.