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.
