MICRO Relational Database Management System: Difference between revisions

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The '''Micro DBMSInformation Management System''' was the first-large scale [[set -theoretic]] [[database management system]] to be used in production.<ref name=Hershey1972>[https://docs.google.com/open?id=0B4t_NX-QeWDYNmVhYjAwMWMtYzc3ZS00YjI0LWJhMjgtZTYyODZmNmFkNThh "A set theoretic data structure and retrieval language" (PDF)], William R. Hershey and Carol H. Easthope, Paper from the Session on Data Structures, Spring Joint Computer Conference, May 1972 in ''ACM SIGIR Forum'', Volume 7, Issue 4 (December 1972), pp. 45-55, DOI=[http://doi.acm.org/10.1145/1095495.1095500 10.1145/1095495.1095500]</ref> Its major underpinnings and algorithms were based on the setSet-theoreticTheoretic Data Structure (STDS) model ofdeveloped by D. L. Childs of the University of Michigan's CONCOMP (Conversational Use of Computers) Project.<ref name=North2010>[http://drdobbs.com/blogs/database/228700616 "Sets, Data Models and Data Independence"], by Ken North a Dr. Dobb's Blogger, March 10, 2010</ref><ref>[http://hdl.handle.net/2027.42/4163 ''Description of a set-theoretic data structure''], D. L. Childs, 1968, Technical Report 3 of the CONCOMP (Research in Conversational Use of Computers) Project, University of Michigan, Ann Arbor, Michigan, USA</ref><ref>[http://hdl.handle.net/2027.42/4164 ''Feasibility of a Set-Theoretic Data Structure : A General Structure Based on a Reconstituted Definition of Relation''], D. L. Childs, 1968, Technical Report 6 of the CONCOMP (Research in Conversational Use of Computers) Project, University of Michigan, Ann Arbor, Michigan, USA</ref> ItMicro providedfeatured a natural language interface which allowed non-programmers to use the system.<ref name=MICROManual1977>[http://docs.google.com/viewer?a=v&pid=explorer&chrome=true&srcid=0B4t_NX-QeWDYZGMwOTRmOTItZTg2Zi00YmJkLTg4MTktN2E4MWU0YmZlMjE3 ''MICRO Information Management System (Version 5.0) Reference Manual''], M.A. Kahn, D.L. Rumelhart, and B.L. Bronson, October 1977, Institute of Labor and Industrial Relations (ILIR), University of Michigan and Wayne State University</ref>

Implementation of Micro began in 1970 as part of the Labor Market Information System (LMIS) project at the University of Michigan's Institute of Labor and Industrial Relations (ILIR).<ref runningname=MICROManual1977/> underFunding came from the [[MichiganOffice Terminalof System]],Manpower theAdministration [[S/360]]within andthe [[U.S/370]]. time-sharingDepartment systemof developed at U-MLabor. It was first used for the study and analysis of micro-statistics contained in the United States Census data base; hence the name of the system. Organizations such as the [[United States Department of Labor|US Department of Labor]], the [[United States Environmental Protection Agency|US Environmental Protection Agency]], and researchers from [[University of Alberta]], the [[University of Michigan]], [[Wayne State University]], the [[University of Newcastle upon Tyne]], and [[Durham University]] used Micro to manage very large scale databases. It continued to be used in production until 1998.

Micro runs under the [[Michigan Terminal System]], the interactive time-sharing system developed at U-M that runs on IBM [[S/360]], [[S/370]], and compatible mainframe computers.<ref>[http://babel.hathitrust.org/cgi/pt?view=image;size=100;id=mdp.39015014920717;page=root;seq=5 "Chapter 6: MICRO" in ''Introduction to database management systems on MTS''], Rick Rilio, User Guide Series, Computing Center, University of Michigan, March 1986, pages 147-189</ref> Micro provides a query language, a database directory, and a data dictionary to create an interface between the user and a collection of very efficient collection of proprietary Set-Theoretic Data Structure (STDS) software developed by the Set-Theoretic Information Systems Corporation (STIS) of Ann Arbor, Michigan. The lower level routines from STIS treat the data bases as sets and perform set operations on them, e.g., union, intersection, restrictions, etc. Although the underlying STDS model is based on set theory, the Micro user interface is similar to those subsequently used in [[relational database management systems]].<ref>[http://dx.doi.org/10.1145/362384.362685 "A Relational Model of Data for Large Shared Data Banks"], E.F. Codd, Communications of the ACM, volume 13, issue 6 (June 1970), pp. 77–387, doi= 10.1145/362384.362685</ref><ref name=North2010/> MICRO's data representation can be thought of as a matrix or table in which the rows represent different records or "cases", and the columns contain individual data items for each record; however, the actual data representation is in set-theoretic form. In labor market applications the rows typically represent job applicants or employees and columns represent fields such as age, sex, and income or type of industry, number of employees, and payroll.<ref name=Hershey1972/>

The underlying data model and retrieval algorithms used by Micro were deeply influenced by D. L. Childs' Set Theoretic Data Model. The Set Theoretic Data Model also influenced the [[Relational database|relational model]] later made famous by [[Edgar F. Codd]], a research scientist at IBM.<ref>[http://dx.doi.org/10.1145/362384.362685 "A Relational Model of Data for Large Shared Data Banks"], E.F. Codd, Communications of the ACM, volume 13, issue 6 (June 1970), pp. 77–387, doi= 10.1145/362384.362685</ref><ref name=North2010/> Although the underlying model was based on set theory, the Micro user interface provided a query language similar to those subsequently used in [[relational database management systems]].

Micro permittedpermits users with little programming experience to define, enter, interrogate, manipulate, and update collections of data in a relatively unstructured and unconstrained environment. An interactive system, Micro wasis powerful in terms of the complexity of requests which couldcan be made by users without prior programming language experience.<ref>"[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2581360/pdf/procascamc00021-0314.pdf Use of a Relational Database to Support Clinical Research: Application in a Diabetes Program]", Diane Lomatch, M.P.H., Terry Truax, M.S., Peter Savage, M.D., Diabetes Center Unit, MDRTC, University of Michigan, 1981</ref> Micro includedincludes basic statistical computations such as mean, variance, frequency, median, etc. If more rigorous statistical analysis wereare desired, the data from a Micro database couldcan be usedexported withto the Michigan Interactive Data Analysis System (MIDAS),<ref>[http://babel.hathitrust.org/cgi/pt?id=mdp.39015004498013;page=root;view=image;size=100;seq=3;num=i ''Documentation for MIDAS''], Daniel J. Fox and Kenneth E. Guire, Third Edition (September 1976), Statistical Research Laboratory, University of Michigan, 203 pp.</ref> a statistical analysis package available under the [[Michigan Terminal System]] (MTS).<ref>"[http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2245120/pdf/procascamc00019-0674.pdf Converting from Traditional File Structures to Database Management Systems: A Powerful Tool for Nursing Management"], Yvonne Marie Abdoo, Ph.D., R.N, Wayne State University College of Nursing, 1987</ref><ref>[http://babel.hathitrust.org/cgi/pt?view=image;size=100;id=mdp.39015014920717;page=root;seq=5 "Chapter 6: MICRO" in ''Introduction to database management systems on MTS''], Rick Rilio, User Guide Series, Computing Center, University of Michigan, March 1986, pages 147-189</ref>

== References ==