Model 204

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Model 204 is a database management system for IBM and compatible mainframe computers, “born” 1965 October 13,[1]:66[2] and first deployed in 1972. It incorporates a programming language and an environment for application development. Implemented in assembly language[2] for IBM System/360 and its successors, M204 can deal with very large databases[citation needed] and transaction loads of 1000 TPS.[1]:4

Model 204 relies on its own type of bitmap index, originally devised by Professor Patrick E. O'Neil, and combines the use of hash table, B-tree, and record list technologies to optimize speed and efficiency of database access.[3][4]

Although M204 is a pre-SQL (and pre-relational) database product, it is possible to manually map the files of an M204 database to approximate SQL equivalents and provide some limited SQL functionality using Model 204 SQL Server.[5]

Model 204 is most commonly used in government and military applications.[citation needed] Among other things, it runs Australia's social security system (Centrelink).[6][7] It is used commercially in the UK by Marks & Spencer.[citation needed] It is also used at the Ventura County Property Tax system in California,[8] the Harris County, Texas, Justice Information Management System,[9] and in the New York City Department of Education's Automate The Schools system. An informal list of past and present Model 204 users, compiled in 2010, identified more than 140 organizations worldwide.[10] Beginning in 1986, it was used by the US Navy Fleet Intelligence Center Europe and Atlantic (FICEURLANT).[11]

It is a product of Computer Corporation of America (CCA). In April 2010, CCA was acquired by Rocket Software, a Boston-based developer of enterprise infrastructure products.[12]

Add-on products were formerly available from Sirius Software, Inc., located in Cambridge, Massachusetts, USA; in 2012, Sirius Software was also acquired by Rocket Software.[13]

See also[edit]


  1. ^ a b Scinta, Gina (2005-10-10). "Model 204 v6r1: Opening New Doors" (PDF). Computer Corporation of America. Archived from the original (PDF) on January 24, 2013. Retrieved 2012-10-26. 
  2. ^ a b "Model 204, A Novel DBMS and Application Platform". Sirius Software. Retrieved 2012-10-26. 
  3. ^ O'Neil, Patrick (1987). "Model 204 Architecture and Performance". Proceedings of the 2nd International Workshop on High Performance Transaction Systems. Springer-Verlag. pp. 40–59. 
  4. ^ Sandy Stanhope, Database Administrator. "What is Model 204?". The Youngstown State University Computing Newsletter. Department of Computer Services. Retrieved 11 January 2008. 
  5. ^ "Rocket Model 204 SQL Server Users Guide". Rocket Software. May 2012. Retrieved 2012-10-27. 
  6. ^ Rodney Gedda (Techworld Australia) (May 2009). "Centrelink ups IT reform, keeps Model 204 'legacy'". Retrieved 9 February 2011. 
  7. ^ "County of Ventura Technology Infrastructure Strategic Plan" (PDF). Gartner. 2005-07-13. p. 43. Retrieved 2012-10-25. 
  8. ^ "Model 204 Civil Inquiry Manual" (PDF). Harris County, Texas. June 2007. Retrieved 2012-10-25. 
  9. ^ Paul Keshvari; et al. (2010). "M204 Client List". Archived from the original on 2013-11-11. Retrieved 2012-10-28. 
  10. ^ Fleet Intelligence Center Europe and Atlantic: Command History: 1 January 1986 – 31 December 1986. United States Navy. pp. III–B–3, III–B–7. Retrieved 2016-05-02. 
  11. ^; acquired June 13, 2010
  12. ^ Seiffert, Don (2012-11-29). "Rocket Software buys fifth company this year". Boston Business Journal. Retrieved 2016-05-02. 

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