Chapter 11 Database Management 11.1 Overview In flat databases 21, records are organized according to a simple list of entities; many simple data bases for personal computers are flat in structure. The records in hierarchical data bases are organized in a treelike structure, with each level of records branching off into a set of smaller categories. Unlike hierarchical databases, which provide single links between sets of records at dififerent levels network databases create multiple linkages between sets by placing links, or pointers, to one set of records in another; the speed and versatility of network data bases have led to their wide use in business 在非结构化的数据库中,按照实体的一个简单列表组织记录;很多个人 计算机的简易数据库是非结构的。层次型数据库按树型组织记录,每 层的记录分解成更小的属性集。层次型数据库在不同层的记录集之间提 供一个单一链接,与此不同,网络型数据库在不同记录集之间提供多个 链接,这是通过设置指向其它记录集的链或指针来实现的。网络型数据 库的速度及多样性使其在企业中得到广泛应用。 雾语1Chapter 11 Database Management 计算机专业英语 11-7 In flat databases [2] , records are organized according to a simple list of entities; many simple databases for personal computers are flat in structure. The records in hierarchical databases are organized in a treelike structure, with each level of records branching off into a set of smaller categories. Unlike hierarchical databases, which provide single links between sets of records at different levels, network databases create multiple linkages between sets by placing links, or pointers, to one set of records in another; the speed and versatility of network databases have led to their wide use in business. 在非结构化的数据库中，按照实体的一个简单列表组织记录；很多个人 计算机的简易数据库是非结构的。层次型数据库按树型组织记录，每一 层的记录分解成更小的属性集。层次型数据库在不同层的记录集之间提 供一个单一链接，与此不同，网络型数据库在不同记录集之间提供多个 链接，这是通过设置指向其它记录集的链或指针来实现的。网络型数据 库的速度及多样性使其在企业中得到广泛应用。 11.1 Overview