A release migration could be a DB2 version-to-version upgrade
(such as migrating from DB2 for z/OS Version
9 to DB2 for z/OS Version
10) or a DB2 maintenance level upgrade (such as applying an APAR or
a PTF). A release migration might introduce new features and change
the behavior of the DB2 SQL optimizer. Rebinding a DB2 package after
a release migration might change the access plan for the SQL statements
and affect performance.
In this scenario, you can compare access plans for SQL statements
from packages to determine if performance has regressed or improved.
Tip: You should specify as the source a collection
(that is, a group of packages) that contains the access plan and packages
from before the release migration. You should specify as the target a
collection that contains the access plans and packages from after
the release migration, after running the REBIND command on the packages.