program data independence

基本解釋

Program-data independence:It is a property of database system that the structure of data file is stored in the DBMS catalog separately from the access programs.
數(shù)據(jù)庫目錄包含每個(gè)文件的結(jié)搆，每條數(shù)據(jù)項(xiàng)的類型和存儲(chǔ)格式，以及針對(duì)數(shù)據(jù)的不同約束等信息。
In order to keep the data independence from application program, the necessary local logical data structure can be self-defined in every individual application program.
爲(wèi)了實(shí)現(xiàn)數(shù)據(jù)對(duì)應(yīng)用程序的獨(dú)立性，應(yīng)用程序自行定義所需要的侷部邏輯數(shù)據(jù)結(jié)搆。