Set up replica identity index for RoleOverride

refs FOO-1171
flag=none

test plan:
 - migration works up and down
 - tests pass

Change-Id: I944d86adc191e5cb18a2129546e1661ae6197b78
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/260529
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
Reviewed-by: Simon Williams <simon@instructure.com>
QA-Review: Michael Ziwisky <mziwisky@instructure.com>
Product-Review: Michael Ziwisky <mziwisky@instructure.com>

db/migrate/20210312061724_add_replica_identity_for_role_overrides.rb

@@ -0,0 +1,33 @@
+# 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 AddReplicaIdentityForRoleOverrides < ActiveRecord::Migration[6.0]
+  tag :postdeploy
+  disable_ddl_transaction!
+
+  def up
+    add_replica_identity 'RoleOverride', :root_account_id, 0
+    remove_index :role_overrides, column: :root_account_id, if_exists: true
+  end
+
+  def down
+    add_index :role_overrides, :root_account_id, algorithm: :concurrently, if_not_exists: true
+    remove_replica_identity 'RoleOverride'
+    change_column_null :role_overrides, :root_account_id, true
+  end
+end

lib/data_fixup/fix_select_final_grade_for_existing_accounts.rb

@@ -28,6 +28,11 @@ module DataFixup
       all_select_final_grade_overrides = RoleOverride.where(permission: 'select_final_grade')
       all_ta_and_related_roles = Role.where(base_role_type: 'TaEnrollment')
       site_admin = Account.site_admin
+      # this fixup gets run from a migration that takes place before the
+      # root_account_id column is added to the table.  it also gets run from
+      # its own specs which execute after said column is added.  so both
+      # versions of the table need to be accommodated.
+      add_root_account_id = RoleOverride.column_names.include?('root_account_id')
 
       # The case where moderate_grades RoleOverrides exist for non-ta roles.
       all_moderate_grades_overrides.where(enabled: false).find_in_batches do |moderate_overrides|
@@ -47,7 +52,9 @@ module DataFixup
             enabled: moderate_override.enabled,
             locked: moderate_override.locked,
             role_id: moderate_override.role_id
-          }
+          }.tap do |override|
+            override.merge!(root_account_id: moderate_override.root_account_id) if add_root_account_id
+          end
         end
 
         RoleOverride.bulk_insert(new_role_overrides)
@@ -81,7 +88,9 @@ module DataFixup
               enabled: false,
               locked: false,
               role_id: ta_role.id
-            }
+            }.tap do |override|
+              override.merge!(root_account_id: account.resolved_root_account_id) if add_root_account_id
+            end
           end
         end
         RoleOverride.bulk_insert(new_role_overrides)

spec/lib/data_fixup/populate_root_account_id_on_models_spec.rb

@@ -655,13 +655,6 @@ describe DataFixup::PopulateRootAccountIdOnModels do
       end
     end
 
-    context 'with RoleOverride' do
-      it_behaves_like 'a datafixup that populates root_account_id' do
-        let(:record) { RoleOverride.create!(account: reference_record, role: Role.first) }
-        let(:reference_record) { account_model }
-      end
-    end
-
     context 'with Score' do
       it_behaves_like 'a datafixup that populates root_account_id' do
         let(:record) { reference_record.scores.create! }