Single-phase reorganization
For a performance gain, you can combine the UNLOAD and RELOAD phases into a single processing phase, named REORG. You do so by setting the value of the UNLOAD command or installation option to RELOAD.
The following considerations apply to single-phase reorganizations:
When running a single-phase reorganization with SHRLEVEL NONE (the default), you can omit the following data sets:
- For a table space reorganization, the SYSREC data set
- For an index reorganization, the SYSUT1 data set
Omitting the data set provides a performance boost. However, if you omit the data set, your job might not be restartable.
When running a single-phase reorganization with SHRLEVEL REFERENCE or SHRLEVEL CHANGE, REORG PLUS does not use the following data sets, even if specified:
- For a table space reorganization, the SYSREC data set
- For an index reorganization, the SYSUT1 data set
For SHRLEVEL REFERENCE, the job is restartable due to the nondestructive nature of this type of reorganization.
For SHRLEVEL CHANGE, REORG PLUS is not restartable until the UTILTERM phase begins. There is no need to restart the job before the UTILTERM phase begins because the original data sets are not modified.
For detailed usage requirements for the SYSREC and SYSUT1 data sets, see the following references:
For information about restarting the job during a single-phase reorganization, see Restarting-REORG-PLUS.
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