Defining Segments, Files, and Areas › Segments, Files, and Areas › Areas

Areas

The following section Discusses related areas of database segment.

Range of Database Pages

An area is a contiguous range of database pages. Each page maps to one or more blocks in a file associated with the area.

Related Areas Generally Share Same Segment

Areas that contain related information are usually defined within the same segment. For example, the Commonweather database has three areas within one segment: one for employee information (EMP-DEMO-REGION), one for organizational information (ORG-DEMO-REGION), and one for benefits information (INS-DEMO-REGION).

An Area Maps to Files

Each area can map to one or more physical files. In turn, one file can contain the pages of one or more areas.

What an Area Defines

When you define an area, you assign the following attributes:

• The area's initial page range and pages reserved for future expansion
• The size of each page in the area and, optionally, a cushion reserved for expansion of variable-length records, internal index records, and compressed records and rows
• Optionally, for SQL-defined databases, whether to maintain a synchronization stamp for each table in the area or a single stamp for the entire area
• Optionally, for non-SQL defined databases, symbolic parameter values
• The file or files that contain the area's pages

Note: For more information about sizing areas and planning their use, see the CA IDMS Database Design Guide.