Add FK to hashed_storage_migrated_event_id column on the geo_event_log table

db/migrate/20171107144726_add_geo_hashed_storage_migrated_events_foreign_key.rb

+class AddGeoHashedStorageMigratedEventsForeignKey < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_foreign_key :geo_event_log, :geo_hashed_storage_migrated_events,
+                               column: :hashed_storage_migrated_event_id, on_delete: :cascade
+  end
+
+  def down
+    remove_foreign_key :geo_event_log, column: :hashed_storage_migrated_event_id
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20171107144122) do
+ActiveRecord::Schema.define(version: 20171107144726) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -2280,6 +2280,7 @@ ActiveRecord::Schema.define(version: 20171107144122) do
   add_foreign_key "gcp_clusters", "projects", on_delete: :cascade
   add_foreign_key "gcp_clusters", "services", on_delete: :nullify
   add_foreign_key "gcp_clusters", "users", on_delete: :nullify
+  add_foreign_key "geo_event_log", "geo_hashed_storage_migrated_events", column: "hashed_storage_migrated_event_id", name: "fk_27548c6db3", on_delete: :cascade
   add_foreign_key "geo_event_log", "geo_repositories_changed_events", column: "repositories_changed_event_id", name: "fk_4a99ebfd60", on_delete: :cascade
   add_foreign_key "geo_event_log", "geo_repository_created_events", column: "repository_created_event_id", name: "fk_9b9afb1916", on_delete: :cascade
   add_foreign_key "geo_event_log", "geo_repository_deleted_events", column: "repository_deleted_event_id", name: "fk_c4b1c1f66e", on_delete: :cascade