12 Codd’s Rules in Relational Database Management System
12 Codd’s Rules in Relational Database Management System Introduction Codd's twelve rules are a set of thirteen rules ( numbered zero to twelve ) proposed by Edgar F. Codd , a pioneer of the relational model for databases , designed to define what is required from a database management system in order for it to be considered relational , i.e., a relational database management system (RDBMS). They are sometimes referred to as "Codd's Twelve Commandments". History Codd originally set out the rules in 1970 , and developed them further in a 1974 conference paper. His aim was to prevent the vision of the original relational database from being diluted, as database vendors scrambled in the early 1980 s to repackage existing products with a relational veneer. Rule 12 was particularly designed to counter such a positioning. In 1999 a textbook s...