Database Support For A Three Level Store

传统上，DBMS假定所有可访问的数据 驻留在磁盘上，占用少量数据 主存储器高速缓存中的空间。 未来的对象管理器将 要求管理非常大的对象库， 关键对象永久驻留在主存中，其他 对象驻留在磁盘上，其余的对象占用第三层空间 记忆此外，可能存在三个以上的存储级别 目前，其中一些可能存在于偏远地区。这 一个项目研究了一个DBMS的体系结构，它可以支持 在单个软件系统中的多级存储。该方法是 要概括和应用文件系统、查询 优化，并将数据类型抽象为多个级别， 存储. 此外，由于存储可能存在于多个 计算机系统，来自分布式数据库的想法也必须 应用。这项研究的意义在于， 大规模的问题得到了解决。 具体来说，新一代 数据库管理系统正在发展，将支持更通用的应用程序 而不是由关系型 数据库管理系统 下一个前沿是克服戏剧性的规模 增加了这些新应用程序所需成本。

Traditionally, DBMSs have assumed that all accessible data resides on magnetic disk with small amounts of data occupying space in a main memory cache. Future object managers will be called on to manage very large object bases in which time critical objects resides permanently in main memory, other objects are disk resident, and the remainder occupy tertiary memory. Moreover, there may be more than three levels of storage present, and some of them may exist at remote locations.This project investigates the architecture of a DBMS that can support a multi-level store in a single software system. The approach is to generalize and apply ideas from file systems, query optimization, and abstract data types to multiple levels of storage. In addition, since storage may exist on multiple computer systems, ideas from distributed data bases must also be applied. The significance of this research is that the issue ofmassive size is addressed. Specifically, a new generation of DBMSs is unfolding that will support more general applications than the business data processing ones addressed by relational DBMSs. The next frontier is to overcome the dramatic size increase that these new applications entail.