With the technological development , more and more original data shall be acquired and processed and a large amount of intermediate data and result data will be produced in processing . pure digital data have developed to multimedia data such as sound and image ones , so that there are more demands for advanced data management . moreover , the system calls for higher integration degree even on - line real - time processing in many cases , and its integration with network and distributed processing need considering as well 隨著科學(xué)技術(shù)的發(fā)展,采集、處理的原始數(shù)據(jù)量越來越大,且在處理過程中將產(chǎn)生大量的中間數(shù)據(jù)和結(jié)果數(shù)據(jù);數(shù)據(jù)已經(jīng)從純粹的數(shù)字?jǐn)?shù)據(jù)發(fā)展到聲音、圖像等多媒體數(shù)據(jù),對數(shù)據(jù)管理的要求越來越高;系統(tǒng)集成度越來越高,在許多場合要求聯(lián)機(jī)實(shí)時(shí)處理,并需要考慮與網(wǎng)絡(luò)的集成,進(jìn)行分布處理。