This Natural profile parameter selects and activates or deactivates single or multiple new or changed Natural features supplied as selectable units.

For more information, see Selectable Units for New Natural Features in the Operations documentation.

Possible settings	OFF	All selectable units (Natural features) are deactivated; any keyword subparameter settings are switched off.
	Un={ON|OFF}	One or more selectable units (Natural features) are activated (ON) or deactivated (OFF) with the keyword subparameter Un: see SELUNIT Parameter Syntax. The SHOWSU system command lists all selectable units available in your Natural environment and the selectable units that have been specified and activated. You can also use the SU line command/keyword of the SYSPROD system command to check whether selectable units are active.
Default setting	OFF
Dynamic specification	yes
Specification within session	no

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Selectable Units Available

The following selectable unit is available on z/OS:

Unit

Feature

U1

Compression and decompression of Natural threads by the Natural Roll Server during roll-out and roll-in operations. This reduces CPU usage by the Natural nucleus, and thus CPU consumption of the hosting TP system (CICS or IMS TM) or the Natural server (Natural RPC server or Natural Development Server). The compression routines run on an IBM System z Integrated Information Processor (zIIP), if available, improving overall performance of Natural.

SELUNIT Parameter Syntax

The following syntax applies:

SELUNIT={OFF|({Un={ON|OFF}},...) }

Where:

n is a number from 1 to 24, each representing a specific feature as announced in Changed/Enhanced Profile Parameters in the current Natural Release Notes for Mainframes.

Example of SELUNIT Parameter

SELUNIT=(U1=ON,U4=OFF)