Guaranteed resource allocation (GRA)

You can use scheduler rules or resource group assignments to classify plans into different groups, then use guaranteed resource allocation (GRA) to arrange for each group to receive a different portion of system resources.

The net system resources are the system resources that are available to process user (including admin) jobs, that is, the total system resources minus those resources that are needed to process special, high-priority system jobs.

A resource group is a Netezza Performance Server group whose resource settings (that is, its resource minimum, resource maximum, and job maximum) determine what portion of the net system resources are to be allocated to plans that are associated with that group. For example, you might create three different resource groups for the plans of data analysts, users who produce query reports, and all other users, then arrange for each of these groups to receive a different fraction of the net system resources.

Each Netezza Performance Server system has at least one resource group. This group has the name Public and cannot be dropped. When a user is created, if the user is not explicitly assigned to a resource group, the user is assigned to the Public group by default. You can change a user's resource group assignment.

Each plan that is processed by a Netezza Performance Server system is associated with exactly one resource group. If no other resource groups are created for a system, all plans are associated with the Public group. However, you can create additional resource groups and associate plans with these groups based on any combination of the following criteria:

Which user submitted the corresponding job

Each user is assigned to exactly one resource group. Each time a user submits a job, the plans for that job are automatically associated with the user's resource group.

You can use scheduler rules to override a plan's resource group association based on the submitting user. For example, the following scheduler rule associates all plans for jobs submitted by the user bob with the resource group rsg42, regardless of the resource group to which bob is assigned:

IF USER IS bob THEN EXECUTE AS RESOURCEGROUP rsg42

The contents of the client information fields

An administrator or application program can set the following client information fields in a query:

User ID: The user ID under which the client is running.
Application name: The name of the client.
Workstation name: The host name of the workstation on which the client runs.
Accounting string: The value of the accounting string from the client information that is specified for the session.

You can use scheduler rules to associate plans with different resource groups based on the contents of these fields (see Client information). For example, the following scheduler rule associates all plans for jobs submitted by the application named Cognos with the resource group rsg12:

IF CLIENT_APPLICATION_NAME IS Cognos THEN EXECUTE AS RESOURCEGROUP rsg12

Cost estimates

For each plan, the optimizer calculates the expected cost of processing that plan. You can use scheduler rules to associate plans with different resource groups based on their calculated cost estimates. For example, the following scheduler rules associate plans with the resource groups with the names "short", "medium", and "long" based on the plans' cost estimates:

IF ESTIMATE < 4 THEN EXECUTE AS RESOURCEGROUP short
IF ESTIMATE >= 4 ESTIMATE < 30 THEN EXECUTE AS RESOURCEGROUP medium
IF ESTIMATE >= 30 THEN EXECUTE AS RESOURCEGROUP long

The database that is to be accessed

You can use scheduler rules to associate plans with different resource groups based on which databases the plans access. If different tenants access different databases exclusively, you can use this capability to manage resource allocation based on tenancy. For example, the following scheduler rules associate plans with different resource groups based on which database they access:

IF DATABASE IS dbx1 THEN EXECUTE AS RESOURCEGROUP x1
IF DATABASE IS dbx2 THEN EXECUTE AS RESOURCEGROUP x2

The table that is to be accessed

You can use scheduler rules to associate plans with different resource groups based on which tables the plans access. In this way, a database administrator can influence resource allocation to applications without changing the applications themselves. For example, the following scheduler rule associates a plan with resource group x2 if it accesses table tab1 or tab2:

IF TABLE IN (tab1,tab2) THEN EXECUTE AS RESOURCEGROUP x2

Custom tags

You can add any number of tags to sessions (see Tags). All the plans that are within the scope of that session receive the same tag. You can also create scheduler rules that add tags directly to all plans that meet the conditions specified by the rule. You can then use scheduler rules to associate plans with different resource groups based on these tags. For example, the following scheduler rule associates a plan with a resource group based on whether one or more of the specified tags have been set for the plan or its session:

IF TAG IN (eod,eom,eoy) THEN EXECUTE AS RESOURCEGROUP endjobs