add content tags index for due date cacher

Change-Id: I3acf7efce4413e4dcb9ae88024b7c51ab5ce8eb1
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/271169
Reviewed-by: Keith Garner <kgarner@instructure.com>
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
QA-Review: Cody Cutrer <cody@instructure.com>
Product-Review: Cody Cutrer <cody@instructure.com>

db/migrate/20210811142037_content_tags_due_date_cacher_index.rb

@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+#
+# Copyright (C) 2021 - present Instructure, Inc.
+#
+# This file is part of Canvas.
+#
+# Canvas is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License as published by the Free
+# Software Foundation, version 3 of the License.
+#
+# Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+# A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Affero General Public License along
+# with this program. If not, see <http://www.gnu.org/licenses/>.
+
+class ContentTagsDueDateCacherIndex < ActiveRecord::Migration[6.0]
+  disable_ddl_transaction!
+  tag :postdeploy
+
+  def change
+    add_index :content_tags,
+              [:content_type, :context_type, :context_id],
+              where: "workflow_state<>'deleted'",
+              name: 'index_content_tags_for_due_date_cacher',
+              algorithm: :concurrently,
+              if_not_exists: true
+  end
+end