Computer Corporation Of America Research Articles

International Data Base

The concept of the International Data Base (IDB) grew from recognition of the need for timely, high quality information on the demographic, social and economic characteristics of foreign countries. During the past 2 decades, the Bureau of the Census, US Department of Commerce, has been compiling, analyzing and evaluating international demographic data and, to a lesser extent, socioeconomic data with particular emphasis on developing countries. In 1979, at the request of the Office of Women in Development at the Agency for International Development, a computerized data base of demographic and socioeconomic statistics that could be used to assess the status of women in developing countries was established. The major categories of data now being included in IDB are as follows: population by age and sex; vital rates, infant mortality and life tables; health and nutrition; fertility and child survivorship; migration; provinces and cities; family planning; ethnic, religious and language groups; literacy and education; labor force, employment, income and gross national product; and household size and housing indicators. The Bureau, through its Center for International Reserch (CIR), developed a computerized central depository of demographic, social and economic data for all countries of the world to serve the needs of the public and private sectors. The initial emphasis was on demographic and social data, since these subject areas are those for which a vast amount of data has already been compiled, analyzed and evaluated by CIR staff. However, meetings are being planned with users to determine the additional types of data that are desired, particularly in the economic and health-related areas. IDB includes data for all countries of the world, by urban and rural residence. The time coverage is from 1950 to the present. Data sources include: population and industrial censuses and surveys, administrative records, population registers, statistical publications, research papers, and personal communication with foreign officials and researchers. Quality and quantity of data varies from country to country, depending on the quality of field work, the sample design, the accuracy of information given by respondents, the adequacy of tabulations or publications, and specification or knowledge of data needs. Data for each country are presented according to the definitions prescribed by that country; no attempt has been made by the Bureau to standardize definitions of concepts. Model 204, a data base management system developed by the Computer Corporation of America, was adopted for the IDB project. Technical details of this system are provided in the annex, as well as lists of tables included in the IDB.

A tool kit for database programming in Ada

This paper describes an Ada-compatible database application development environment being designed and prototyped at Computer Corporation of America. This environment is intended to provide uniform access to centralized, homogeneously distributed, and heterogeneously distributed databases. There are two key interfaces: an interactive interface called Daplex which is based on a semantically rich data model and a powerful access language, and an application program interface called Adaplex which consists of an expression level integration of Daplex with Ada. The objective of this paper is to explain our rationale for designing Adaplex and to describe its support environment.

Office procedures as a distributed database application

An office proedure specification system is described. The system is to be implemented as a database application in a distributed database management system being developed at Computer Corporation of America. Because of its data-base application characteristic, the system treats form copying and routing differently from other office information systems. This differences makes controlling and tracing forms easier than it is in other systems. We also introduce a generalized trigger, called trigger-lock, for synchronizing independently created procedures and for exception handling.

Comparison of four relational data model specifications

This paper reviews four different approaches to specifying the relational data model which are written at about the same time:1. the 'Definition and Formalization of the Relational Data Model' as provided as part of the final ANSI/X3/SPARC/DBSSG Relational Database Task Group Report,2. the 'Relational Database Model Specifications' as submitted to the National Bureau of Standards by the Computer Corporation of America as a draft report in October 1981,3. the 'Formal Definition of the Relational Model' as specified by C. Date of IBM, San Jose, and4. the specification of the relational data model which is expressed in terms of the 'Positional Set Notation' as given in the 'Abstract Database Model' project of the National Bureau of Standards in October 1981.The paper points out some of the differences between the four approaches to specifying the RDM semantics.

The automated desk

The Automated Desk is an online, spatial interface to a time-shared computer utility. It supports a user in organizing, locating, and handling computerized information and tools. Naive computer users benefit from the ability to use the power of an operating system without knowing operating system commands. Experienced programmers benefit from the ability to “browse” a large number of “virtual terminals,” each running instances of various software programs. All users benefit from the ability to access computer-resident information while retaining the familiar visual orientation of the office desk. The user sees his “desk top” through an intelligent display terminal that is connected to a host computer. The desk top is a large flat surface about 100 times the size of an ordinary desk top. On it, the user can place objects in groupings that are meaningful to him. Processes can be associated with these objects to perform any online information handling function. The Automated Desk is a derivative of the Spatial Data Management System (SDMS) implemented by Computer Corporation of America. In the Automated Desk, the essential SDMS concepts of spatial organization and pictorial identification are implemented in simple ways on equipment of modest cost. The objective of the Automated Desk is to put key SDMS-like capabilities into an inexpensive product that runs on widely-available equipment. It is intended for widespread use in practical applications.

Reliability mechanisms for SDD-1

This paper presents the reliability mechanisms of SDD-1, a prototype distributed database system being developed by the Computer Corporation of America. Reliability algorithms in SDD-1 center around the concept of the Reliable Network (RelNet). The RelNet is a communications medium incorporating facilities for site status monitoring, event timestamping, multiply buffered message delivery, and the atomic control of distributed transactions. This paper is one of a series of companion papers on SDD-1 [3, 4, 6, 13].

Introduction to a system for distributed databases (SDD-1)

The declining cost of computer hardware and the increasing data processing needs of geographically dispersed organizations have led to substantial interest in distributed data management. SDD-1 is a distributed database management system currently being developed by Computer Corporation of America. Users interact with SDD-1 precisely as if it were a nondistributed database system because SDD-1 handles all issues arising from the distribution of data. These issues include distributed concurrency control, distributed query processing, resiliency to component failure, and distributed directory management. This paper presents an overview of the SDD-1 design and its solutions to the above problems. This paper is the first of a series of companion papers on SDD-1 (Bernstein and Shipman [2], Bernstein et al. [4], and Hammer and Shipman [14]).

Concurrency control in a system for distributed databases (SDD-1)

This paper presents the concurrency control strategy of SDD-1. SDD-1, a System for Distributed Databases, is a prototype distributed database system being developed by Computer Corporation of America. In SDD-1, portions of data distributed throughout a network may be replicated at multiple sites. The SDD-1 concurrency control guarantees database consistency in the face of such distribution and replication. This paper is one of a series of companion papers on SDD-1 [4, 10, 12, 21].

The correctness of concurrency control mechanisms in a system for distributed databases (SDD-1)

This paper presents a formal analysis of the concurrency control strategy of SDD-1. SDD-1, a System for Distributed Databases, is a prototype distributed database system being developed by Computer Corporation of America. In SDD-1, portions of data distributed throughout a network may be replicated at multiple sites. The SDD-1 concurrency control guarantees database consistency in the face of such distribution and replication. This paper is one of a series of companion papers on SDD-1 [2, 8].

The Concurrency Control Mechanism of SDD-1: A System for Distributed Databases (The Fully Redundant Case)

SDD-1, A System for Distributed Databases, is a distributed database system being developed by Computer Corporation of America (CCA), Cambridge, MA. SDD-1 permits data to be stored redundantly at several database sites in order to enhance the reliability and responsiveness of the system and to facilitate upward scaling of system capacity. This paper describes the method used by SDD-1 for updating data that are stored redundantly.

More on Go

In the article "Go and the Computer" which you reprinted from Go Review, Stuart Dowsey presents a brief laymen's eye view of my work. Here is a somewhat more detailed glimpse. This work was done primarily in 1971 and 1972 as a hobby, using available time on a PDP-10 at Computer Corporation of America.