Software Distributor Administration Guide for HP-UX 11i

Managing Patches
Introduction
Chapter 5166
• Another new option, autoselect_patches, causes SD to
automatically select patches that are appropriate for any non-patch
software that has been selected.
• Patch dependencies are now enforced. See “Patch Supersession and
Dependency Resolution” on page 166 and “Using swlist to Resolve
Manual Dependencies” on page 179.
Patch management command options are discussed in the following
sections.
Patch Supersession and Dependency Resolution
Because patches can be superseded, special considerations are made
when resolving dependencies on patches. By definition, a patch that
supersedes another patch is assumed to be able to satisfy any
dependencies that exist on the superseded patch. The converse is not
true, however. A superseded patch will not satisfy a dependency on a
superseding patch.
SD-UX uses the information in each patch fileset’s supersedes attribute
to build a supersession chain, which represents the superseding
relationships among patches for a given base fileset.
When resolving a dependency on a patch, SD-UX attempts to find the
latest patch in the corresponding supersession chain. It starts with the
patch specified by the dependency, and traverses the chain until it finds a
non-superseded patch. Thus, a dependency that specifies a given patch
may actually cause a different, superseding patch to be automatically
selected.
You can override this auto-selection behavior by explicitly selecting
patches. If SD-UX encounters an explicitly-selected patch fileset during
the traversal of the supersession chain, that patch is used to resolve the
dependency—even if it is superseded by other patch filesets in the chain.
Note, however, that if the chain has an explicitly-selected patch fileset
that cannot satisfy the dependency (that is, it is superseded by the patch
fileset specified in the dependency), swinstall will treat this as an error
(an attempt to install multiple patch filesets in the same supersession
chain).