With list structures allocated in a coupling facility of CFLEVEL=9 or higher, the new list structure services allow entry key (KEYCOMPARE) and secondary key (SKEYCOMPARE) comparison to be performed to determine whether a list entry should be processed. With the KEYREQTYPE and SKEYREQTYPE keywords, the key comparison can specify that the entry key and the secondary key of the designated list entry be equal, less than or equal, or greater than or equal to a specified value.

When processing single list entries, key comparison is allowed on read, write, move, and delete operations. If the designated entry exists but fails to meet the comparison criterion, the IXLLSTE request is ended.

When processing multiple list entries, the key comparators of less than or equal and greater than or equal have been added to the List Structure Multiple Services requests. For list structures allocated in a coupling facility of CFLEVEL=9 or higher, these request types can also use a range of key values to be compared with the existing entry key. To be selectable for processing, the list entry must have a key value within the specified range.

When processing a list of list entries and locating list entries by keyed position, the key comparators of less than or equal and greater than or equal have been added to the READ_LIST request and are also available with the new DELETE_LIST request. These request types can also use a range of key values for selecting list entries for processing when the list structure is allocated in a coupling facility of CFLEVEL=9 or higher.