PRTV was the world's first relational database management system

Relational database management system

A relational database management system is a database management system that is based on the relational model as introduced by E. F. Codd. Most popular databases currently in use are based on the relational database model....

 that could handle significant data volumes.

It was a relational query system with powerful query facilities, but very limited update facility and no simultaneous multiuser facility. PRTV was a follow-on from the very first relational implementation, IS1

IS1

IS/1 was the world's first relational database system, implemented at the IBM United Kingdom Scientific Centre in Peterlee in the years 1970–1972. It had limited facilities but implemented a true relational model. It was the precursor to PRTV....

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Features

PRTV included several firsts in the relational database area:

• implemented relational optimizer
• implemented cost based relational optimizer
• handle tables of 1000 rows up to 10,000,000 rows
• user defined functions (UDFs) within an RDB (also a large suite of built-in functions such as trigonometric and statistical)
• geographic information system based on an RDB (using UDFs such as point-in-polygon).

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. The PRTV team also introduced surrogates to the relational model to help formalize relational update operations; and a formalisation for updating through views. However neither of these was implemented within PRTV. PRTV emphatically did not implement NULL values, because this conception was introduced only in 1979.

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