Changing a DEDB randomizing routine using online change

If a change is made to a randomizer already in use by one or more DEDBs, then all of the DEDBs using the subject randomizer must be included in the change process.

The changed randomizer will not be introduced if an existing version is already loaded for any DEDB in the active IMS system. You can determine that the existing version is no longer used by locating the keyword GONE in message DFS2838I. Also, you can determine that the randomizer module is brought from any library to the storage by locating the keyword LOADED in the message DFS2842I.

Changing DEDB randomizers requires the procedures described below. Because the name of the randomizer remains the same, DBDGEN, ACBGEN and the online change command sequence are not applicable.

Procedure

  1. Use a specific customer-developed application program or OEM utility to unload the DEDB with the existing randomizer. This should be done for all of the DEDBs that use the randomizer to be changed.
  2. Remove access to the DEDBs from the active IMS system by entering the type-1 command /DBR DATABASE or the type-2 command UPDATE DB STOP(ACCESS). The /DBR DATABASE command unloads the randomizer for the DEDBs designated as operands. The UPDATE DB STOP(ACCESS) command also unloads the randomizer for the DEDBs that are designated as operands, unless the OPTION(NORAND) parameter is specified. When all of the DEDBs that reference the randomizer are stopped, the randomizer is removed from the active IMS system. If a DEDB is not stopped and it references a randomizer that has been removed from the IMS system, then the next DL/I call results in a U1021 abend.
  3. Assemble and link edit the changed randomizer into the IMS SDFSRESL or one of the libraries of the IMS SDFSRESL STEPLIB concatenation.
  4. Delete, define and initialize all of the DEDB AREA data sets to prepare for reloading the DEDB with the changed randomizer.
  5. Resume access to the DEDBs that use the changed randomizer by issuing the type-1 command /START DATABASE or the type-2 command UPDATE DB START(ACCESS). For DEDBs, the /START DATABASE command or the UPDATE DB START(ACCESS) command causes the randomizer to be loaded. To resume access to all of the areas at the same time, you can issue the type-2 command UPDATE DB START(ACCESS) AREA(*).
  6. Use a specific customer-developed application program or OEM utility to reload the DEDB with the changed randomizing routine in effect.