This paper is written within the context of a relational data base model as presented by E. F. Codd in . It also serves as a companion paper to his paper .
The central thesis is that a file operation should not produce unexpected 'side effects' in order to maintain a restriction (such as one-one, or many-one) on the file. Any file operation which would violate a restriction for some possible data is called 'violative'. It is determined which cases of the file operations WRITE, REWRITE… CONTINUE READING