EDBMS／3：一个微机环境下的工程数据库管理系统

EDBMS/3:AN ENGINEERING DATABASE MANAGEMENT SYSTEM IN AN MICROCOMPUTER ENVIRONMENT

本文讨论了一个工程数据库管理系统ＥＤＢＭＳ／３的总体结构和功能，以及几个实现技术。该系统在对我们室自行研制的工程数据核心管理系统ＥＤＢＭＳ／２的底层改动和扩充的基础上，提供给用户功能更强的ＤＤＬ和ＤＭＬ。通过对内存常驻数据区、临时数据区和空白区的有效管理，从而减少了常用表的内外存频繁切换，提高了效率。为防止可能出现的系统隐患和数据不一致，定义了元组的Ｒ型网状结构。对多媒体数据的管理和操作使该系统具有处理动态声音、图像等多媒体数据的功能。

This paper discusses an engineering database management system──EDBMS/3.Based on extending and modifying EDBMS/2 which is designed and implemented by CAD Laboratory of the institute of Computing Technology. Academia Sinica,EDBMS/3 supplies stronger capacity of Data Definition Language (DDL) and Data Manipulation Language (DML).The effective management for a resident data area, a transient area and a free area in main memory reduces the table swapping between the main memory and the disk. The paper defines R-type tuple network structure to prevent possible system error and data inconsistency. The management and manipulation for multimedia data means the system has the ability of processing dynamic multimedia data such as a period of sounds and a section of images.