PRTV

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PRTV (Peterlee Relational Test Vehicle) was the world's first relational database management system that could handle significant data volumes — it was really a relational query system and had very powerful query facilities, but very limited update facility and no simultaneous multiuser facility. PRTV was a followon from the very first relational implementation: IS1.

PRTV included several firsts in the relational database area:

implemented relational optimizer (Hall, May 1976)
implemented cost based relational optimizer (Todd, July 1977)
handle tables of 1000 rows (1993) up to 10,000,000 rows (1996) (Storey, 1979)
user defined functions (UDFs) within an RDB (also a large suite of builtin functions such as trigonometric and statistical) (Todd, 1976)
geographic information system based on an RDB (using UDFs such as point-in-polygon) (Aldred, May 1974)

PRTV was based on a relational algebra, Information Systems Base Language (ISBL) and followed the relational model very strictly. Even features such as user defined functions were formalized within that model (Hall, January 1975). The PRTV team also introduced surrogates to the relational model (Hall, 1976) to help formalize relational update operations; and a formalisation for updating through views (Todd, August 1977). However neither of these was implemented within PRTV. PRTV emphatically did NOT implement NULL values, because of the formal problems these pose.

PRTV was itself never available as a product, but the Urban Management System (Aldred, May 1974) built on it was available as a limited IBM product.

References

S J P Todd, "The Peterlee Relational Test Vehicle - A System Overview", IBM Systems Journal, 15,4, pp.285–308, 1976.
HALL, P.A.V. Optimization of a single relational expression in a relational database system. IBM J. Res. Develop. , 244–257.
S J P Todd, "Relational Database Optimisation", Proceedings of Conference: (Sistemi di Basi di Dati, esperienze e ricerche), Venice, Italy, July 1977.
Storey, R, Trebeljahr, W, Ourusoff, N, Bunzel, M, "Report of the World Health Organisation Information Systems Programme and IBM UK Scientific Centre study on the design of information systems", 1979, UKSC Report 105
ALDRED, B. K., AND SMEDLEY, B.S. An urban management system — general overview, Rep. No UKSC-53, IBM UK Scientific Center, Peterlee, England, May 1974.
P A V Hall, P Hitchcock, S J P Todd, "An algebra of relations for machine computation", Conference record of the second ACM Symposium on the Principles of Programming Languages, Palo Alto, California, January 1975.
P A V Hall, J Owlett, S J P Todd, "Relations and entities", Modelling in Data Base Management Systems (ed GM Nijssen), North Holland 1976.
S J P Todd, "Automatic Constraint Maintenance and Updating Defined Relations", Proceedings of the IFIP Congress 1977, Toronto, ed Gilchrist, North Holland, pp.145–148, August 1977.

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