Pages

A page is the physical unit of disk storage that the database server uses to read from and write to HCL Informix® databases.

The following figure illustrates the concept of a page, represented by a darkened sector of a disk platter.

Figure 1. A page on disk

On most UNIX platforms, the page size is 2 KB. On Windows, the page size is 4 KB. Because your hardware determines the size of your page, you cannot alter this value.

A chunk contains a certain number of pages, as the following figure illustrates. A page is always entirely contained within a chunk; that is, a page cannot cross chunk boundaries.

Figure 2. A chunk, logically separated into a series of pages

For information about how the database server structures data within a page, see the chapter on disk structures and storage in the HCL Informix Administrator's Reference