Overview of database file management

File management provides the functions that an application uses in creating and accessing data on the server and ensures the integrity of the data according to the definitions of the application.

Traditional file management, formerly known as data management, is the part of the operating system that controls the storing and accessing of data by an application program. The data might be on internal storage (for example, database), on external media (diskette, tape, printer), or on another system.

File management provides functions that allow you to manage files (create, change, override, or delete) using CL commands, and create and access data through a set of operations (for example, read, write, open, or close). File management also provides you with the capability to access external devices and control the use of their attributes for creating and accessing data.

If you want to make more efficient use of printers and diskette devices, file management provides the capability of spooling data for input or output. For example, data being written to a printer can be held on an output queue until the printer is available for printing.

On the iSeries™ server, each file (also called a file object) has a description that describes the file characteristics and how the data associated with the file is organized into records, and, in many cases, the fields in the records. Whenever a file is processed, the operating system (the Operating System/400® or OS/400® program) uses this description.

You can create and access data on the system by using these file objects. File management defines and controls several different types of files. Each file type has associated CL commands to create and change the file, and you can also create and access data through the operations provided by file management.