Once you have identified the work running on your data
server, you are ready to actively manage this work by assigning resources
and imposing controls.
Resource assignment with service classes
A service class defines an execution environment
in which work can run. This execution environment allocates available
resources and can include thresholds that determine how work is permitted
to run.
Control of work with thresholds
Thresholds permit you to maintain stability in the system.
You create threshold objects in order to catch work that behaves abnormally,
either predictively before the work begins running based on the projected
impact, or reactively as it is running and consuming resources.
Priority aging of ongoing work
Priority aging can automatically change
the priority of in-progress activities over time. You can use priority
aging to control longer-running activities, so that throughput for
shorter-running activities can be improved.
Apply controls to types of activities with work action sets
Work action sets contain work actions
that apply controls to activities of a certain type in a specific
service superclass, in a specific workload, or to the database as
a whole.
Cancelling activities
If an activity is consuming too many resources,
or is running too long, you can cancel it. Cancelling an activity
is gentler than forcing the application that submitted the activity.
A cancelled activity returns SQL4725N to the user, but does not end
the connection or affect any other user activity. Forcing the application
ends both the connection and user activities.