Scientific research relies as much on the dissemination and exchange of data sets as on the publication of conclusions. Accurately tracking the lineage (origin and subsequent processing history) of scientific data sets is thus imperative for the complete documentation of scientific work. Researchers are effectively prevented from

Maintenance tends to degrade the structure of software, ultimately making maintenance more costly. At times, then, it is worthwhile to manipulate the structure of a system to make changes easier. However, it is shown that manual restructuring is an error-prone and expensive activity. By separating structural manipulations from other maintenance activities, the semantics of a system can be held constant by a tool, assuring that no errors are introduced by restructuring. To allow the maintenance team to focus on the aspects of restructuring and maintenance requiring human judgment, a transformation-based tool can be provided---based on a model that exploits preserving data flow-dependence and control flow-dependence---to automate the repetitive, errorprone, and computationally demanding aspects of re...

To separately compile a program module in traditional statically-typed languages, one has to manually write down an import interface which explicitly specifies all the external symbols referenced in the module. Whenever the definitions of these external symbols are changed, the module has to be recompiled. In this paper, we present an algorithm which can automatically infer the "minimum" import interface for any module in languages based on the Damas-Milner type discipline (e.g., ML). By "minimum", we mean that the interface specifies a set of assumptions (for external symbols) that are just enough to make the module type-check and compile. By compiling each module using its "minimum" import interface, we get a separate compilation method that can achieve the following optimal property: A compilation unit never needs to be recompiled unless its own implementation changes.

This dissertation addresses a number of important issues related to interprocedural optimization. Interprocedural optimization is an integral component in a compilation system for high-performance computing. The importance of interprocedural optimization stems from two sources: it increases the context available to the optimizing compiler, and it enables programmers to use procedure calls without the concern of hurting execution time. While important, interprocedural optimization can introduce some significant compile-time costs. When interprocedural information is used to optimize a procedure, the procedure is then dependent on those interprocedural facts. Thus, even if the procedure is not edited, it may require recompilation due to changes in the interprocedural facts. In addition to these effects on recompilation, interprocedural information can also be expensive to compute. Furthermore, interprocedural optimizations can increase program size which can in turn increase compile tim...

This article proposes an overview of the Adele system and also discusses other approaches and other systems. While most of our work on Configuration Management is covered, we have deliberately chosen to discuss in greater depth the Work Space aspect and the relationship between the Repository Space and the WSs

To help us identify and focus on pragmatic and concrete issues related to the role of software architecture in the design and development of large systems, we conducted a survey of a variety of software systems used in industrial applications. Our premise, which guided the examination of these systems, was that software architecture is concerned with capturing the structures of a system and the relationships among the elements both within and between structures. The structures we found fell into several broad categories: conceptual structure, module structure, code structure, and execution structure. These categories address different engineering concerns. The separation of such concerns, combined with specialized implementation techniques, decreased the complexity of implementation, and improved reuse and reconfiguration. We observed that in practice, software architecture played an important role throughout the development process: specification, design, functional decompo...

We present a formulation of interconnection models and present the unit and syntactic models --- the primary models used for managing the evolution of large software systems. We discuss various tools that use these models and evaluate how well these models support the management of system evolution. We then introduce the semantic interconnection model. The semantic interconnection model incorporates the advantages of the unit and syntactic interconnection models and provides extremely useful extensions to them. By refining the grain of interconnections to the level of semantics (that is, to the predicates that define aspects of behavior) we provide tools that are better suited to manage the details of evolution in software systems and that provide a better understanding of the implications of changes. We do this by using the semantic interconnection model to formalize the semantics of program construction, the semantics of changes, and the semantics of version equivalence and compatibi...

With non-traditional application areas such as engineering design, image/voice data management, scientific/statistical applications, and artificial intelligence systems all clamoring for ways to store and efficiently process larger and larger volumes of data, it is clear that traditional database technology has been pushed to its lim-its. It also seems clear that no single database system will be capable of simultaneously meeting the functionality and performance requirements of such a diverse set of applications. In this paper we describe the initial design of EXODUS, an extensible database system that will facilitate the fast development of high-performance, application-specific database systems. EXODUS provides certain kernel facilities, including a versatile storage manager and a type manager. In addition, it provides an architectural framework for building application-specific database sys-tems, tools to partially automate the generation of such systems, and libraries of software components (e.g., access methods) that are likely to be useful for many application domains.

It is generally recognized that the classical transaction model, providing atomicity and serializability, is too strong for certain application areas since it unnecessarily restricts concurrency. We are concerned with supporting cooperative work in multi-user design environments, particularly teams of programmers cooperating to develop and maintain software systems. We present an extended transaction model that meets the special requirements of software engineering projects, describe possible implementation techniques, and discuss a number of issues regarding the incorporation of such a model into multi-user software development environments. To appear in Sixth International Conference on Data Engineering, Los Angeles CA, February 1990. 1 Introduction The focus of this paper is on how to support groups of individuals who are cooperating to achieve common goals in the context of design environments based on object management systems; we are specifically concerned with teams...

Achieving correct changes is the dominant activity in the application software industry. Modification of database schemata is one kind of change which may have severe consequences for database applications. The paper presents a method for measuring modifications to database schemata and their consequences, by using a thesaurus tool. Measurements of the evolution of a large-scale database application currently running in several hospitals in the UK are presented and interpreted. The kind of measurements provided by this in-depth study is useful input to the design of change management tools. Keywords: Schema evolution, change statistics, change management tools. * Published in: Information and Software Technology, Vol. 35, No. 1, pp. 35-44, January 1 1 Introduction One of the most challenging problems of building and maintaining large, long-lived application systems is to cope with all the changes that inevitably will be imposed on the systems over time. Many large application systems...