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.
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.
Control of work with thresholds
You can use thresholds to maintain stability in the system
by identifying work that behaves abnormally. You can identify abnormal
behavior predictively, before the work begins running, based on the
projected impact. You can also identify abnormal behavior reactively,
as the work is running and consuming resources.
Priority aging of ongoing work
Priority aging is an approach to workload
management in which the priority of in-progress activities automatically
changes over time.
Priority mapping based on data accessed
You can prioritize activities based on what data the activity
accesses during activity execution using the DATATAGINSC threshold.
Workload management dispatcher overview
The DB2® workload
management dispatcher is a built-in DB2 technology
by which you can specifically allocate CPU resources to work that
is being executed on a database server. CPU resource entitlements
can be controlled by using CPU shares and CPU limit attributes on DB2 service classes.
Default query concurrency management
To ensure that heavier workloads that use column-organized data
do not overload the system when many queries are submitted simultaneously,
there is a limit on the number of "heavyweight" queries that
can run against a database at the same time.
Canceling activities
If an activity is consuming too many resources, or is running
too long, you can cancel it. Canceling an activity is gentler than
forcing the application that submitted the activity. A canceled 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.