Advanced Topics › Global Data Set Integrity Facility › The Exempt List › Statements in the Exempt List

Statements in the Exempt List

If you specify EXEMPT=YES on a QNAME statement, then GDIF uses the statements in the exempt list to decide whether to propagate requests for that QNAME. GDIF looks at two types of statements in the exempt list: a statement that tells GDIF how to process requests by default and statements that override processing for specific resources or jobs.

You can use the following exempt list statements to indicate how GDIF should process resources:

DEFAULT

Tells GDIF whether to propagate ENQ and RESERVE requests by default when a task requests a QNAME for which EXEMPT=YES is specified.

GLOBAL

Tells GDIF to propagate ENQ and RESERVE requests for a certain resource or job. You also can use this statement to change the way GDIF handles hardware reserves for a resource.

LOCAL

Tells GDIF not to propagate ENQ requests for a certain resource or job. LOCAL statements do not apply to RESERVE requests, unless EXEMPTRESERVES=YES has been specified. Even when this option is set to YES, RESERVES=CONVERT/KEEP cannot be specified on a LOCAL statement (and RESERVES=KEEP is implied).

You can specify only one DEFAULT statement, and it must be the first statement in the exempt list. You can specify as many GLOBAL and LOCAL statements as you need to override processing for specific resources or jobs.

Each of these parameters on a DEFAULT statement affects the way GDIF handles requests by default:

JOB

Tells GDIF whether to propagate requests by default, no matter what job issued the request.

RESOURCE

Tells GDIF whether to propagate requests by default, no matter what RNAME is specified on the request.

While each parameter affects propagation, it is the combined effect of these parameters that determines whether GDIF propagates requests by default and how you can override this default processing:

• When you specify GLOBAL on both parameters, GDIF propagates requests globally. You can override this default processing for ENQ requests using LOCAL statements.
• When you specify LOCAL on one or both parameters, GDIF treats requests as local requests and does not propagate the requests to other systems. You can override this default processing using GLOBAL statements.

GDIF uses a maximum of two matching LOCAL statements, GLOBAL statements, or both for each request: one statement that contains a matching RNAME, and another statement that contains a matching job name. If more than one statement contains a matching RNAME or job name, then GDIF selects one of these matching statements and ignores all other matching statements. Therefore, you need to understand how GDIF chooses among matching statements.