Split migration to add and index namespaces.runners_token

db/migrate/20170906133745_add_runners_token_to_groups.rb

@@ -3,15 +3,7 @@ class AddRunnersTokenToGroups < ActiveRecord::Migration
 
   DOWNTIME = false
 
-  disable_ddl_transaction!
-
-  def up
+  def change
     add_column :namespaces, :runners_token, :string
-
-    add_concurrent_index :namespaces, :runners_token, unique: true
-  end
-
-  def down
-    remove_column :namespaces, :runners_token
   end
 end

db/migrate/20180503150427_add_index_to_namespaces_runners_token.rb

@@ -0,0 +1,14 @@
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class AddIndexToNamespacesRunnersToken < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def change
+    add_concurrent_index :namespaces, :runners_token, unique: true
+  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: 20180430143705) do
+ActiveRecord::Schema.define(version: 20180503150427) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"