add index

db/migrate/20251121092044_add_is_first_to_completed_submitters.rb

@@ -6,7 +6,9 @@ class AddIsFirstToCompletedSubmitters < ActiveRecord::Migration[8.0]
     add_column :completed_submitters, :is_first, :boolean
     # rubocop:enable Rails/ThreeStateBooleanColumn
 
-    add_index :completed_submitters, %i[account_id completed_at], where: 'is_first = TRUE'
+    add_index :completed_submitters, %i[account_id completed_at],
+              where: 'is_first = TRUE',
+              name: 'index_completed_submitters_account_id_completed_at_is_first'
     add_index :completed_submitters, :submission_id, unique: true, where: 'is_first = TRUE'
   end
 end

db/migrate/20251121093511_add_completed_at_index_to_completed_submitters.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+class AddCompletedAtIndexToCompletedSubmitters < ActiveRecord::Migration[8.0]
+  def change
+    add_index :completed_submitters, %i[account_id completed_at],
+              name: 'index_completed_submitters_on_account_id_and_completed_at'
+    remove_index :completed_submitters, :account_id
+  end
+end