Ims Db 简明教程
IMS DB - Overview
A Brief Overview
数据库是关联数据项的集合。这些数据项以提供快速且轻松访问的方式进行组织和存储。IMS 数据库是分层数据库，数据存储在不同级别，每个实体都依赖于更高级别的实体。使用 IMS 的应用程序系统上的物理元素如下图所示。
Database is a collection of correlated data items. These data items are organized and stored in a manner to provide fast and easy access. IMS database is a hierarchical database where data is stored at different levels and each entity is dependent on higher level entities. The physical elements on an application system that use IMS are shown in the following figure.
Database Management
数据库管理系统是一组应用程序，用于存储、访问和管理数据库中的数据。IMS 数据库管理系统通过以易于检索的方式组织数据来维护完整性，并允许快速恢复数据。IMS 通过其数据库管理系统的帮助维护大量世界公司数据。
A Database Management system is a set of application programs used for storing, accessing, and managing data in the database. IMS database management system maintains integrity and allows fast recovery of data by organizing it in such a way that it is easy to retrieve. IMS maintains a large amount of world’s corporate data with the help of its database management system.
Transaction Manager
事务管理器的功能是提供数据库和应用程序之间的通信平台。IMS 充当事务管理器。事务管理器与最终用户打交道，以从数据库存储和检索数据。IMS 可以使用 IMS DB 或 DB2 作为后端数据库来存储数据。
The function of transaction manager is to provide a communication platform between the database and the application programs. IMS acts as a transaction manager. A transaction manager deals with the end-user to store and retrieve data from the database. IMS can use IMS DB or DB2 as its back-end database to store the data.
DL/I – Data Language Interface
DL/I 包含允许访问存储在数据库中的数据的应用程序。IMS DB 使用 DL/I，DL/I 作为程序员在应用程序中访问数据库时使用的接口语言。我们将在接下来的章节中更详细地讨论这一点。
DL/I comprises of application programs that grant access to the data stored in the database. IMS DB uses DL/I which serves as the interface language that programmers use for accessing the database in an application program. We will discuss this in more detail in the upcoming chapters.