EXTEND expands a GDS database file. Databases with a BG access method generally extend automatically when they become full. MM databases must be MUPIP EXTENDed. For MM segments, EXTEND requires exclusive or stand-alone access to the file. When EXTEND requires exclusive database access and cannot obtain it, MUPIP rejects the command.

When the journal file is unable to extend (e.g., if the disk is full), GT.M turns off journaling and no longer generates a GTMASSERT.

EXTEND increases the size of a database file. A database file will automatically extend under normal use. There is usually no need to extend a file with MUPIP.

The format of the EXTEND command is:

         EXTE[ND] /qualifier] region-name
         

The required region-name parameter specifies the name of the region you want to expand. EXTEND uses the Global Directory to map the region to the dynamic segment and the segment to the file.

EXTEND takes one optional qualifier:

/B[LOCKS]=blocks

Specifies the number of GDS database blocks by which MUPIP should extend the file. GDS files use additional blocks for bitmaps. EXTEND adds the specified number of blocks plus the bitmap blocks required as overhead. For more information about bitmaps, refer to the "Greystone Database Structure" chapter.

By default, EXTEND uses the extension value in the file header as the number of GDS blocks by which to extend the database file.