Element selection

SMP/E uses the element statements provided in a SYSMOD to determine which elements should be installed in the target libraries. The selection of elements from a SYSMOD is based on relationships among SYSMODs being installed, other SYSMODs being installed, and modification identifiers of the corresponding elements installed on the target system. Three modification identifiers are kept for each element:

FMID: Function modification identifier
The FMID of an element is the function SYSMOD that owns the element. Generally, an element's FMID is established (and later changed) by the installation of a function SYSMOD. In this case, the element's FMID is the function SYSMOD that installed the element on the target system.
RMID: Replacement modification identifier
The RMID of an element is the last SYSMOD that replaced the element (or caused the element's FMID to change). An element's RMID is established by the SYSMOD that first introduces the element to the target system. The RMID of an element is changed by the installation of a SYSMOD that supplies a replacement for the element. Element replacements are ++MOD, ++MAC, ++PROGRAM, ++SRC, ++JAR, data element, and hierarchical file system element message control statements, and modules resulting from assemblies.
UMID: Update modification identifier
The UMIDs of an element are the set of SYSMODs that have applied updates to the target system element. A UMID is added to the set of the element's UMIDs for each SYSMOD that applies an update to the element. Whenever a new replacement for the element is applied, the set of UMIDs is cleared to start anew with subsequent updates applied to the new replacement. Element updates are ++ZAPs, ++MACUPDs, ++SRCUPDs and ++JARUPDs.

Note: Because data elements, hierarchical file system elements, and program elements can only be replaced and cannot be updated, they do not have UMIDs.

The purpose of element selection is to make sure that the correct functional level of each element is selected and that no service is inadvertently removed from the system.

Element selection in SMP/E is divided into three cases:

The FMID of the SYSMOD being installed matches the FMID of the element on the target system.
The FMID of the SYSMOD being installed differs from the FMID of the element on the target system.
A function SYSMOD is being reinstalled.

The following topics describe processing for each case.