Fix build stages reference migration

db/migrate/20170526185602_add_stage_id_to_ci_builds.rb

@@ -7,15 +7,11 @@ class AddStageIdToCiBuilds < ActiveRecord::Migration
 
   def up
     add_column :ci_builds, :stage_id, :integer
-
     add_concurrent_foreign_key :ci_builds, :ci_stages, column: :stage_id, on_delete: :cascade
-    add_concurrent_index :ci_builds, :stage_id
   end
 
   def down
     remove_foreign_key :ci_builds, column: :stage_id
-    remove_concurrent_index :ci_builds, :stage_id
-
     remove_column :ci_builds, :stage_id, :integer
   end
 end

db/post_migrate/20170526185901_remove_stage_id_index_from_builds.rb

@@ -0,0 +1,17 @@
+class RemoveStageIdIndexFromBuilds < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    if index_exists?(:ci_builds, :stage_id)
+      remove_concurrent_index(:ci_builds, :stage_id)
+    end
+  end
+
+  def down
+    # noop
+  end
+end

db/post_migrate/20170526185921_migrate_build_stage_reference.rb

@@ -3,6 +3,8 @@ class MigrateBuildStageReference < ActiveRecord::Migration
 
   DOWNTIME = false
 
+  disable_ddl_transaction!
+
   def up
     disable_statement_timeout
 

db/post_migrate/20170621102400_add_stage_id_index_to_builds.rb

@@ -0,0 +1,19 @@
+class AddStageIdIndexToBuilds < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    unless index_exists?(:ci_builds, :stage_id)
+      add_concurrent_index(:ci_builds, :stage_id)
+    end
+  end
+
+  def down
+    if index_exists?(:ci_builds, :stage_id)
+      remove_concurrent_index(:ci_builds, :stage_id)
+    end
+  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: 20170614115405) do
+ActiveRecord::Schema.define(version: 20170621102400) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"