Every large business that processes its own data works with record files. Record files contain lines of data that are either field delimited, called a variable-length record file, or each line of data is the same length and each data field is defined by string length and position, called a fixed-length record file. We will look at examples of each record file format type and methods of processing the files quickly and manipulating the data. I added this chapter to this second edition at the request of a co-worker at Coca-Cola Enterprises, Mark Sellers. Mark asked me one day for a quick way to add the name of the record file to the end of every record, or line, in the file. Mark's problem was that when he merged a bunch of record files together in a single file for batch processing, and the batch file had an error with a particular record, he had no idea which record file the record came from. We will look at methods to solve this problem and many others.
A record file is an alphanumeric character flat file (text file) that contains one or more lines of data. Each separate line of data is called a record. A record is made up of different fields that contain the actual data. There are two types of record files: