What: Exodus project software (Storage Manager & GNU E) From: zwilling@caseus.cs.wisc.edu (Mike Zwilling) Date: 16 Jul 92 04:53:19 GMT
In the past there have been discussions in comp.object and comp.databases about persistent storage for object-oriented databases and programming languages. As you may know, the EXODUS Database Toolkit project at the University of Wisconsin has researched these issues and others for a number of years. The purpose of this note is to inform you that the software from the EXODUS project is freely available via anonymous ftp. The EXODUS software includes the EXODUS Storage Manager and the compiler for the E persistent programming language. Also included is documentation, and a suite of test programs for both components. This note briefly describes the software and explains how to obtain it. We currently support DECstation 3100s/5000s and SPARC based workstations. Others have ported the code to HP700s and IBM RS6000s.
The EXODUS Storage Manager is a client-server object storage system which provides "storage objects" for storing data, versions of objects, "files" for grouping related storage objects, and indexes for supporting efficient object access. A storage object is an uninterpreted container of bytes which can range in size from a few bytes to hundreds of megabytes. The Storage Manager provides routines to read, overwrite, and efficiently grow and shrink objects. In addition, the Storage Manager provides transactions, lock-based concurrency control, and log-based recovery.
GNU E is a persistent, object-oriented programming language developed as part of the Exodus project. GNU E extends C++ with the notion of persistent data, program level data objects that can be transparently used across multiple executions of a program, or multiple programs, without explicit input and output operations.
GNU E's form of persistence is based on extensions to the C++ type system to distinguish potentially persistent data objects from objects that are always memory resident. An object is made persistent either by its declaration (via a new "persistent" storage class qualifier) or by its method of allocation (via persistent dynamic allocation using a special overloading of the new operator). The underlying object storage system is the Exodus storage manager, which provides concurrency control and recovery in addition to storage for persistent data.
The current release of GNU E is based on gcc/g++ version 2.2.2, and is upward compatible with C++ as implemented by that compiler.
A bibliography of EXODUS related papers can be obtained from the ftp site described below.
To obtain the software, simply ftp to ftp.cs.wisc.edu (128.105.8.18), login as anonymous with your email address as a password, "cd" to the "exodus" directory, and follow the directions (directions will be given as you "cd"). See the README for the latest information about the software and an indication of our future plans. If you decide to use the software, please contact us at exodus@cs.wisc.edu so that we can notify you of changes.
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