Defining Segments, Files, and Areas › Planning › Mapping Areas to Files

Mapping Areas to Files

One area can be stored in multiple files and a single file can contain many areas. Typically, there is a one-to-one correspondence between an area and a file unless:

• The resulting file would be larger than a single disk device, in which case multiple files are used to contain the area
• VSAM is being used as the underlying access method and the area is larger than 4Gb, in which case the area must be mapped to multiple files
• There are a number of small, non-volatile areas, in which case multiple areas may be contained in a single file

Note: For more information about mapping areas to files, see the CA IDMS Database Design Guide.