A scalable online transaction processing system or database management system is one that can be upgraded to process more transactions by adding new processors, devices and storage, and which can be upgraded easily and transparently without shutting it down.
Eksempel: Et skalerbart online transaktionssystem eller et Database Management System er et system, der kan opgraderes til at behandle flere transaktioner ved at tilføje nye processorer, udstyr og lagring, og som kan blive opgraderet let og gennemskueligt uden at måtte lukke systemet ned.