Altering the definition of an online HALDB database

By specifying the ALTER option of the INITIATE OLREORG command, you can apply certain segment or field definition changes to an online HALDB database without stopping access to the database.

During the reorganization process, application programs that use the existing database structure can continue to access the database. Application programs that use the altered database structure cannot access the database until the reorganization process is complete and you perform one of the following actions to enable access to the new segment and field definitions:
  • If you use ACB libraries, the online change function.
  • If the IMS management of ACBs is enabled and you use the IMS catalog, issue the IMS type-2 IMPORT DEFN SOURCE(CATALOG) command.
The ALTER option is currently supported by the following database access types:
  • PHDAM
  • PHIDAM
You can use the ALTER option to make only the following changes to a database definition:
  • An increase to the length of a segment.
  • The addition of new fields to existing, undefined space at the end of a segment.

When the ALTER option is specified, the database is altered by the integrated HALDB online reorganization function. Therefore, unless otherwise noted, the procedures, guidelines, requirements, and so forth that are documented for the integrated HALDB online reorganization function apply when altering a HALDB database.