Introduction to Sequential Files
An important characteristic of a programming language designed for enterprise or business computing is that it should have an external, rather than an internal focus. It should concentrate on processing data held externally in files and databases rather than on manipulating data in memory through linked lists, trees, stacks, and other sophisticated data structures. Whereas in most programming languages the focus is internal, in COBOL it is external. A glance at the table of contents of any programming book on Java, C, Pascal, or Ruby emphasizes the point. In most cases, only one chapter, if that, is devoted to files. In this book, over a quarter of the book deals with files: it covers such topics as sequential files, relative files, indexed files, the SORT, the MERGE, the Report Writer, control breaks, and the file-update problem.