Improve various queries against account domains (#25126)

db/migrate/20230524194155_add_index_instances_on_reverse_domain.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+class AddIndexInstancesOnReverseDomain < ActiveRecord::Migration[6.1]
+  disable_ddl_transaction!
+
+  def change
+    add_index :instances, "reverse('.' || domain), domain", name: :index_instances_on_reverse_domain, algorithm: :concurrently
+  end
+end