Workload management

The workload consists of user-initiated jobs such as SQL queries, administration tasks, backups, and data loads, and system-initiated jobs such as regenerations and rollbacks. Workload management (WLM) is the process of assessing a system's workload and allocating the resources used to process that workload.

A Netezza system attempts to run all of its jobs as fast as possible. If only one job is active on the system, the system devotes all of its resources to completing that job. If two jobs of equal priority are active, the system gives half of its available resources to each job. Similarly, if 40 jobs of equal priority are active, each job receives 1/40th of the available resources. This form of resource allocation is called a fair-sharing model.

However, when running jobs concurrently you might want the system to prioritize certain jobs over others. WLM involves classifying jobs and specifying resource allocation rules so that the system assigns resources based on a predetermined service policy.

Some Netezza service policies are predefined and cannot be modified. For example:
  • The admin user account has special characteristics that prioritize its work over the work of other users.
  • Certain types of system jobs have a higher priority than user jobs or other, less-important system jobs.