Sams Teach Yourself COBOL in 24 Hours

Hour 14Indexed Files

An Indexed file is a file that allows access to data records by way of a Key field. The file is said to be “Indexed” by this Key. Indexed files are sometimes referred to as keyed files. In this hour, you learn the basics of Indexed file handling, such as

• Defining an Indexed file

• Handling Primary and Alternate Keys

• Writing records with an Indexed file

• Using File Status values

• Using Declaratives

A record in an Indexed file contains at least one Key field. This field is the index to the file. There must be at least one Key field that contains a value that is unique. This Key field is the Primary Key. Each record in the file is uniquely identified by this Key, which functions like a serial number. With this Key you ...