The following table shows the HiRDB (unit) setup/startup conditions and availability of plug-ins.

Table 5-1 HiRDB (unit) setup/startup conditions and availability of plug-ins

Plug-in utilization declaration (pdplugin operand)	Registration of plug-in (pdplgrgst)	Plug-in initialization error	Whether a unit can be started	Availability of plug-in
Not specified	Registered	None	S	--
		Occurred	S	--
	Not registered	None	S	--
		Occurred	S	--
Specified	Registered	None	S	S
		Occurred	S	--
	Not registered	None	S	--
		Occurred	S	--

S: Unit can be started, and plug-in can be used.

--: Unit cannot be started, nor can plug-in be used.

Plug-ins are initialized automatically during HiRDB startup. If multiple pdplugin operands are specified in the system common definition and at least one of them results in a plug-in initialization error, none of the plug-ins in the unit can be used.

The availability of plug-ins depends on conditions at the unit in the following cases:

• The plug-in utilization declaration (pdplugin operand) in the system common definition is not the same from one unit to another.
• An error occurred during plug-in initialization processing and the plug-in is no longer available on that unit.

An SQL statement that calls only the available plug-ins will execute successfully; however, if it attempts to call even one unavailable plug-in, execution of the SQL statement will fail.