Types of execution classes

An execution class is a specific combination of execution attributes that specify values for task priority and task-to-thread pool affinity (or task-to-engine affinity in process mode). You can bind an execution class to one or more execution objects, which are client applications, logins, service classes, and stored procedures.

There are two types of execution classes—predefined and user-defined. Adaptive Server provides three predefined execution classes:

Objects associated with EC2 are given average preference for engine resources. If an execution object is associated with EC1, Adaptive Server considers it to be critical and tries to give it preferred access to resources.

Any execution object associated with EC3 is considered to be least critical and does not receive resources until the execution objects associated with EC1 and EC2 are executed. By default, execution objects have EC2 attributes.

To change an execution object’s execution class from the EC2 default, use sp_bindexeclass, described in “Assigning execution classes”.

Create user-defined execution classes by combining the execution attributes in ways that best reflect your site’s needs. Reasons for doing this include: