Nan C. Shu

EXPRESS: a data EXtraction, Processing, and Restructuring System

EXPRESS is an experimental prototype data translation system which can access a wide variety of data and restructure it for new uses. The system is driven by two very high level nonprocedural languages: DEFINE for data description and CONVERT for data restructuring. Program generation and cooperating process techniques are used to achieve efficient operation. This paper describes the design and implementation of EXPRESS. DEFINE and CONVERT are summarized and the implementation architecture presented. The DEFINE description is compiled into a customized PL/1 program for accessing source data. The restructuring specified in CONVERT is compiled into a set of customized PL/1 procedures to derive multiple target files from multiple input files. Job steps and job control statements are generated automatically. During execution, the generated procedures run under control of a process supervisor, which coordinates buffer management and handles file allocation, deallocation, and all input/output requests. The architecture of EXPRESS allows efficiency in execution by avoiding unnecessary secondary storage references while at the same time allowing the individual procedures to be independent of each other. Its modular structure permits the system to be extended or transferred to another environment easily.

Specification of Forms Processing and Business Procedures for Office Automation

Business activities, in general, involve data processing (such as queries, extraction, manipulation, and restructuring of data, etc.) as well as conventional office work centered around preparation, distribution, and filing and retrieval of documents. Convinced that most of these activities can be expressed in terms of forms, we present in this paper a formal means for specification of forms processing. The underlying concept is that business functions can be decomposed into meaningfuliy connected form processes where each process either produces or modifies a form. Powerful constructs are provided so that most of the common data processing activities can be expressed in a very high level, concise, and yet compilable manner.

A general methodology for data conversion and restructuring

This paper presents a methodology and a model for data conversion or translation. The model assumes that both source and target systems are available and that conversion interfaces may be required to interact between these systems and the conversion system. To achieve data conversion or translation using this approach, two languages are needed: 1) a language to describe the data structures, and 2) a language to specify the mapping between source and target data. This paper describes these two languages, DEFINE and CONVERT and gives numerous examples to show the capabilities of these languages and how they can be used in data conversion and restructuring. Both languages are high level and nonprocedural and have the power to deal with most situations encountered in data conversion processes. In addition, the paper also describes some of the facilities in the languages specifically designed for data checking in a data conversion process.

OPAS: an office procedure automation system

This paper discusses an experimental system being developed to support office automation. The emphasis of the paper is on a technology that allows people to automate their office and business activities. Specifically, using forms as the interface, the authors propose a powerful data manipulation and restructuring facility that not only allows users to extract and manipulate data in the forms, but can be used to interface between new and existing applications as well. Since business and office procedures are not discrete activities, but a structured sequence of activities, a means to define and execute procedures is required. Such means is described in this paper along with its model and an example of its application.

A high-level data manipulation language for hierarchical data structures

In this paper we assert that the hierarchical view of data will continue to be popular for a broad class of applications and users. In particular, some of these applications require complex data manipulation which, heretofore, has been dealt with procedurally. In this light, a nonprocedural language, CONVERT, is proposed as a high-level DBMS interface. CONVERT is meant to provide users with a tool for performing complex data manipulation and query of hierarchical data abstractions, called “Forms”. Included in the paper are a description of the Form data abstraction and the CONVERT language, as well as a complete illustrative sample application.

Architecture to an interactive migration system (AIMS)

Growth in the computer industry produces a need to convert data and/or programs from one system to another from time to time. While this process has been going on for years, the techniques used to execute this task have been ad hoc and expensive. Very few aids exist on the market today to help this process. Examination into the conversion scenario reveals that the structure of a system to aid conversion should have the following features: (1) ability to extract pertinent information from high level source application programs and source systems environment. (2) interactive facility where users and the conversion aid system can work together to make the decisions. (3) ability to carry out the translation process automatically after directions are given from a high level language. This paper describes the architecture of such a system and gives the motivations which lead to such conclusions.