Slow query execution when an answer in a plan is saved

[gjacob24]

Problem: When a user edits an answer in a plan, it takes 30-50 seconds to save and this is causing the DMPonline service to crash, because we have a large amount of plans.
Cause: The query in answers_controller.rb is retrieving all the answers with question ID 'YYY' first and then filtered the results with the plan ID 'XXX'.

answers_controller.rb (lines 89-96)

      @plan = Plan.includes(
        sections: {
          questions: %i[
            answers
            question_format
          ]
        }
      ).find(p_params[:plan_id])