When a space shortage occurs in an RDAREA, the size of the RDAREA can be expanded by means of automatic addition of segments, provided that there is sufficient free space in the HiRDB file system area. This process is called RDAREA automatic extension. Figure 7-18 illustrates RDAREA automatic extension.

Figure 7-18 RDAREA automatic extension

A set of contiguous areas in a HiRDB file system area is called an extent. The maximum number of extents for a single HiRDB file is 24. With automatic extension, the number of extents does not increase if contiguous free space can be secured in the last extent allocated in the target HiRDB file. However, if non-contiguous free space is allocated, the number of extents is increased. Extent information can be checked with the pdfls command. Fragmentation of free space in a HiRDB file system area can occur because previously allocated extents may be deleted or their sizes may be reduced when an RDAREA is deleted, reinitialized (its allocation size is reduced or the with reconstruction operand is specified), or integrated. Caution must be exercised if you add, extend, or reinitialize an RDAREA while it is in this status, because multiple extents may be allocated to a single HiRDB file regardless of whether or not automatic extension is being performed.

Organization of this subsection

(1) RDAREAs eligible for automatic extension

(2) Setting automatic extension