next up previous
Next: References Up: An Object Oriented Linkbase Previous: Future Work

The Next Generation of Exodus

  In beginning of 1994, Wisconsin University announced a new persistent object system called SHORE (Scalable Heterogeneous Object REpository) under the final stages of development at their Computer Science Department. SHORE represents a merge of object oriented databases and file system technologies. The goal of this approach is to enable applications to move their data out of files into a modern persistent object repository. In SHORE, as in Unix, named objects can be directories, symbolic links or individual (typed) objects (the counterpart of Unix "plain" files). Unlike Unix, SHORE allows each object to be accessed by a globally unique OID (Object IDentifier). SHORE directory objects provide the same facilities as Unix directories. Familiar Unix concepts such as path name, subdirectory, parent directory, link (both hard and symbolic), and root directory are all defined as they are in Unix. It also provides access control similar to Unix.

SHORE provides a language called SDL (SHORE Data Language), which allows users to describe the types, and then a language specific tool is used to derive a set of class declarations and special purpose function definitions from the typed object. In SHORE, the methods associated with SDL interfaces can be written using any of the languages for which a SHORE language binding exists. At the moment, only C++ binding is operational. This SHORE capability allows databases built by an application written in one language (e.g., C++) to be accessed and manipulated by applications written in another object oriented language (like CLOS, for instance). SHORE has a symmetric peer-to-peer structure. Every participating processor runs a SHORE server regardless of whether it has local disks. SHORE provides the usual set of type constructors: enumerations, arrays, structures, and references (which are used to define relationships). In addition, SHORE provides a variety of bulk types including sets, lists, and sequences, that enable a SHORE object to contain a collection of references to other objects. These are only some characteristics of SHORE, for more information see [CAREY94]. The advantages of SHORE over Exodus are:

As a conclusion and an observation, we can say, that SHORE would have been very welcome if it had been available a few months ago. The idea of a file system augmented with database features or a DBMS with file system features would perhaps have made our job much easier. In a hypermedia system, all documents could be treated as objects and manipulation of all hypermedia feature on documents much easier and clean. Features like version control, would also be implemented in a much easier and safe way. For more information about Shore see reference [9] and www page http://www.cs.wisc.edu/shore/.



next up previous
Next: References Up: An Object Oriented Linkbase Previous: Future Work



Fri Dec 8 14:32:43 GMT 1995