Restore index on services.type

db/migrate/20190107151020_add_services_type_index.rb

+# frozen_string_literal: true
+
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class AddServicesTypeIndex < ActiveRecord::Migration[5.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_index :services, :type unless index_exists?(:services, :type)
+  end
+
+  def down
+    remove_concurrent_index :services, :type if index_exists?(:services, :type)
+  end
+end

db/schema.rb

@@ -2860,6 +2860,7 @@ ActiveRecord::Schema.define(version: 20190404231137) do
     t.boolean "confidential_note_events", default: true
     t.index ["project_id"], name: "index_services_on_project_id", using: :btree
     t.index ["template"], name: "index_services_on_template", using: :btree
+    t.index ["type"], name: "index_services_on_type", using: :btree
   end
 
   create_table "shards", force: :cascade do |t|