METHOD FOR CONTROLLING DUPLICATION OF DISTRIBUTION MAIN MEMORY DATABASE

摘要

PURPOSE: A method for controlling duplication of distribution main memory database is provided to maintain a consistency with respect to duplicate data and increase a reading availability thereof. CONSTITUTION: It is checked whether a reading transaction with respect to 'A','B','C' data items is generated(401) and all locks are obtained(402). If all locks are not obtained, it is checked whether a copy is a primary copy(403). If the copy is not a primary copy, it is checked whether a secondary copy is the latest version(409). If a secondary copy is the latest version, a shared lock is requested(410). It is checked whether the lock is successful(411). If the lock is not successful, a delay is processed(412) and it is checked whether all locks are obtained(402). If a secondary copy is not the latest version, a lock request is transmitted and a lock is waited(413). It is checked whether lock acquisitions from all primary copies are successful(414). If the lock acquisitions are successful, a transmission is prepared(416). The preparation is checked(417) and the transmission is completed(418), and the completion is checked to all primary copies(419).