Introduction

G-EXEC was one of the first relational database management systems, developed in the early 1970s by a team in the UK Institute of Geological Sciences (now the British Geological Survey), but its ideas and design concepts are still just as valid today.

One of the big problems in relational database management has always been the treatment of missing data. The SQL 'NULL' is generally accepted to be an abomination, but Date, Pascal, and others have reacted to this by attempting to forbid the use of any missing data representation in relational databases. they have done this by re-defining the relational database in terms of the 'closed world assumption'. This states that anything not included within the database is false.

However, it was never Codd's intention that the relational model should be restricted in this way, and he explicitly accepted that both closed-world and open-world assumptions have their place. Using the open world assumption may require the use of multi-valued logic, but this is not the insuperable obstacle which Chris Date presents.

A new system, G-EXEC₂, is to be developed using the relational principles as defined by E.F. Codd.

This web site will chart the progress of the development of this software, and related developments such as new database definition and query languages which will be needed.