一种支持SDAI的数据库模式定义语言

A DATA DESCRIBE LANGUAGE OF DATABASE SUPPORTING SDAI

目前，许多应用领域，如ＣＡＤ、ＣＡＳＥ、ＭｕｌｔｉＭｅｄｉａ、ＭＩＳ等对数据库有了新的要求，这就使得面向对象的数据库（ＯＯＤＢ）成为国内外数据处理领域中非常具有诱惑力的一个研究方向。ＯＳＣＡＲ（Ｖ２．０）是浙江大学计算机系自行研制的一个ＯＯＤＢ系统，本文介绍了ＯＳＣＡＲ的数据描述语言（ＤＤＬ），它支持ＳＴＥＰ标准下的标准数据存取接口（ＳＤＡＩ）。本文详细地描述了ＯＳＣＡＲ对数据字典的信息管理策略，以及这些策略为ＳＤＡＩ提供的底层支持，并举例说明了ＤＤＬ是如何为ＳＤＡＩ服务的，ＯＳＣＡＲ中ＤＤＬ的灵活性为ＯＳＣＡＲ系统提供了强大的建模功能，使其独具特色。

Object -oriented database becomes much attractire in data processing recently. OSCAR(V2.0) is an object -oriented database management system which has been worked out by computer science department of ZheJiang University. A new data describe language (DDL) supporting STEP is introduced in this paper. STEP (Standard for the Exchange of Product Model Data) supplies SDAI(Standand Data Access Interface), and this standard obtains most of programers and end -users in engineering fields. Data dictionary records all of the message needed by SDAI. The solution of schema management supporting SDAI is also described in this paper.