An open abstract-object storage system

Abstract

Database systems must become more open to retain their relevance as a technology of choice and necessity. Openness implies not only databases exporting their data, but also exporting their services. This is as true in classical application areas as in non-classical (GIS, multimedia, design, etc).This paper addresses the problem of exporting storage-management services of indexing, replication and basic query processing. We describe an abstract-object storage model which provides the basic mechanism, ' likeness ', through which these services are applied uniformly to internally-stored, internally-defined data, and to externally-stored, externally-defined data. Managing external data requires the coupling of external operations to the database system. We discuss the interfaces and protocols required of these to achieve correct resource management and admit efficient realisation. Throughout, we demonstrate our solutions in the area of semi-structured file management; in our case, geospatial metadata files.