udpate_passengers.rb

    Passenger.find_in_batches batch_size: 1000  do |passengers|
      execute <<-SQL 
        UPDATE passengers AS p 
          SET cruise_index = crs.name,
              person_index = person.name
        FROM passengers, enquiries e, tours t, directions d, cruises crs,
             (SELECT id, name FROM ( 
                SELECT p.id, concat(coalesce(par.first_name, c.first_name), ' ',coalesce(par.last_name, c.last_name)) AS name 
                  FROM passengers p 
                  LEFT JOIN partners par 
                    ON p.partner_id = par.id 
                  LEFT JOIN customers c 
                    ON c.id = p.customer_id) as t where name <> ' ') as person
          WHERE p.enquiry_id = e.id 
            AND e.tour_id  = t.id 
            AND t.direction_id = d.id 
            AND d.cruise_id = crs.id
            AND p.id = person.id
            AND passengers.id in (#{passengers.map(&:id).join ','})
      SQL
    end