With SP 5.2 and above and a structure allocated in a coupling facility with CFLEVEL=1 or higher, you can alter the size of the structure to increase capacity or the entry-to-element ratio to reapportion the structure's storage. As with the rebuild function, you can alter the structure only if the CFRM policy that defines the structure allows for a larger size. You can issue the IXLALTER macro or notify the operator to issue the SETXCF START,ALTER command to initiate structure alter.

For keyed list structures allocated in a coupling facility with CFLEVEL=3, you cannot alter the structure to change the number of EMCs in the structure. However, if the keyed list structure is allocated in a coupling facility of CFLEVEL=4 or higher, you can alter the number of EMCs in the structure.