7.4.1 Function

RDAREA expansion is a function that adds HiRDB files to an RDAREA when the initially estimated RDAREA size becomes insufficient. An RDAREA is expanded by adding component HiRDB files.

Files can be added to an RDAREA up to the maximum of 16 files. An RDAREA can be expanded even while a table or index contained in the RDAREA is being referenced by another user. RDAREA expansion has no effect on the data already contained in the RDAREA.

Figure 7-2 provides an overview of the use of the database structure modification utility (pdmod) for RDAREA expansion.

Figure 7-2 Overview of database structure modification utility (pdmod): RDAREA expansion

[Figure]

Note
If you have extended an RDAREA, be sure to make a backup copy of the RDAREA as well as the other RDAREAs that need to be backed up at the same time. For details about how to back up RDAREAs, see the HiRDB Version 8 System Operation Guide.
Prerequisites
  1. To expand an RDAREA, first you need to initialize the HiRDB file system areas for creation of HiRDB files.
  2. An RDAREA subject to expansion must be in one of the following statuses:
    • Master directory RDAREA
      Shutdown release and open status
    • Data directory RDAREA, data dictionary RDAREA, data dictionary LOB RDAREA, user RDAREA, user LOB RDAREA, registry RDAREA, or registry LOB RDAREA
      [Figure]RDAREA open timing set to INITIAL: Shutdown release status or open status but shut down by command
      [Figure]RDAREA open timing set to DEFER or SCHEDULE: Shutdown release status, open status but shut down by command, or shutdown release and closed status
      To specify the RDAREA open timing, use the pd_rdarea_open_attribute and pd_rdarea_open_attribute_use operands in the system common definitions. For details about these operands, see the HiRDB Version 8 System Definition. You can check the current RDAREA open timing using the pddbls command.
  3. When you expand an RDAREA, check that the maximum number of RDAREA component files in the system common definition (pd_max_file_no) will not be exceeded. If this value is exceeded, you must use the pdchgconf command to change the system common definition or terminate the HiRDB system normally and then change the system common definition.
  4. A shared RDAREA that is expanded is regarded as having been expanded at every back-end server (even if a back-end server has no shared RDAREA, the system assumes that an RDAREA has been expanded). If the maximum permissible number of HiRDB files constituting RDAREAs is exceeded at any of the back-end servers, the shared RDAREA cannot be expanded at all.