Application of work actions to database activities
One, and only one work action set can
be applied to a database, a service superclass, or a workload.
When work is submitted to the data server, it is associated with
a workload, either a user-defined workload or the default workload,
then mapped to a service class.
The following figure shows the process of how a work action is
applied to an activity.Figure 1. Application
of a work action to an activity
A work action is assigned to an activity as follows:
When an activity is mapped to a service superclass or a service
subclass, the data server checks whether an enabled database-level
work action set exists.
If an enabled database-level work action set exists, the data
server then checks whether the activity falls under any of the work
classes in the work class set that the database-level work action
set is associated with.
If the activity falls under a work class and that work class has
any work actions applied to it, those work actions are applied to
the activity.
The data server checks whether an enabled workload-level
work action set exists. If it does, the data server then checks whether
the activity falls under any of the work classes in the work class
set that the workload-level work action set is associated with.
If the activity falls under a work class and
that work class has any work actions applied to it, those work actions
are applied to the activity.
Next, if the activity is mapped by the workload to a service superclass,
the data server checks whether a work action set is applied to the
service superclass.
If a work action set is applied to the service superclass, the
data server then checks whether the activity falls under any of the
work classes in the work class set that the service superclass-level
work action set is associated with.
If the activity falls under a work class and that work class has
any work actions applied to it, those work actions are applied to
the activity.
Note that, if a mapping work action is applied to a stored procedure,
then depending on whether the WITH NESTED or WITHOUT NESTED clause
is specified in the work action definition, child activities of a
stored procedure can run in the same service subclass or in different
service subclasses than the parent activity.
In the following situations an activity is not affected by a work
action set:
Activities fall in the default system (SYSDEFAULTSYSTEMCLASS)
and default maintenance (SYSDEFAULTMAINTENANCECLASS) service classes.
Activities are assigned to the default administration workload,
SYSDEFAULTADMWORKLOAD.
Activities are inside a load operation. The load operation itself
does go through work action set evaluation.
Child activities of system stored procedures. The only exception
is the SYSPROC.ADMIN_CMD stored procedure. Child activities of SYSPROC.ADMIN_CMD
go through work action set evaluation.
The work action set is disabled.
The workload maps the activity directly to a service subclass.