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Although some relational information systems have recently become available for production use, very few, if any of them, contain facilities to collect performance data. This paper describes a method for implementing a performance monitor and some of the data collected by this performance monitor which was recently installed in the REGIS (RElational General Information System). REGIS is currently being used within General Motors.The performance monitor is used to collect data about the usefulness of the command language, performance improvements following major system upgrades and performance predictions based on past runs. While installing the performance monitor several system deficiencies were uncovered.Correction of the deficiencies has already improved performance by almost an order of magnitude. Future improvements are expected to improve performance by at least another order of magnitude.

A study of commands in a relational database system was undertaken to provide a basis for improving future implementations of relational techniques. The use of Regis (Relational General Information System), an interactive relational database system developed at General Motors Research Laboratories, was monitored to accumulate a large amount of data about distribution of command uses across a variety of applications developed by users with a diverse set of capabilities. Of the basic relational commands, it is important that searching, PROJECTION, and JOIN operations be efficient. However, optimizing INTERSECTION and "exclusive or" may not warrant the time and effort it would require. Although proportions of use varied, the rankings of use of relational operations were reasonably independent of applications and the programming expertise level of the users.

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