Modifying Non-SQL Defined Databases › Changes to Schemas and Subschemas › REORG and UNLOAD/RELOAD Utility Statements

REORG and UNLOAD/RELOAD Utility Statements

What REORG and UNLOAD/RELOAD Do

The REORG and UNLOAD/RELOAD utility statements reorganize databases by unloading existing records and reloading them into another database. To reorganize a database, you follow one of two approaches:

• Use the UNLOAD utility statement to offload data to an intermediate file. Use the RELOAD utility statement to store the record data into another database, build index structures, and connect related records together in set structures.
• Use the REORG utility statement to both offload and reload data.

The choice of which approach to use depends on a number of factors:

• The operating system in which the utility is to execute. Currently, REORG is only supported in z/OS.
• The size of the database and the amount of time that you have available to reorganize it. REORG uses parallel processing to reduce the elapsed time that it takes to reorganize a database.
• The types of changes being made. The REORG utility supports more types of changes and in certain cases makes implementing those changes easier. For example, the REORG utility allows you to:
  • Change the CALC key of a record without unloading and reloading twice
  • Change the fields comprising an index key
  • Change the order of an index

  Note: For more information about the types of changes that can be made through the two utilities, see the CA IDMS Utilities Guide.

Steps for unloading and reloading a database

To make changes using REORG or UNLOAD/RELOAD, follow the procedure described in 32.2.2, "Procedure for Modifying the Non-SQL Definitions", adding the steps listed in the following table.

Note: For more information about REORG, UNLOAD and RELOAD, see the CA IDMS Utilities Guide.