characteristics. One job can belong to only one job class, though you can change the job class that a given job is assigned to. Any defined job class can belong to a single resource consumer group, and to a single service at any given time.
Job classes, then, allow you to assign jobs of different priorities. For example, administrative jobs (such as backups) might be assigned to an administrative class that is assigned to a resource group that allows for unconstrained activity. Other jobs, with a lesser priority, may be assigned to job classes that are assigned to resource groups that constrain the overall operational overhead of the job, so that those jobs do not inordinately interfere with other, higher-priority jobs. Thus, job classes help you to manage the amount of resources that a given job can consume.
To create a job class, you use the dbms_scheduler.create_job_class procedure. All classes belong to the SYS schema, and to create one requires the manage scheduler privilege. Here is an example of defining a job class:
exec dbms_scheduler.create_job_class( job_class_name=>'CLASS_ADMIN', resource_consumer_group=>'ADMIN_JOBS', service=>'SERVICE_B');
This job class will be called CLASS_ADMIN. It is assigned to a resource consumer group (that will have already been created) called ADMIN_JOBS, which will no doubt give administrative jobs pretty unfettered access to resources. This job class is also assigned to a specific service, SERVICE_B, so the administrator can define which service the job class is associated with.
Once the job class is defined, you can define which jobs are members of that class when you create the jobs. Alternatively, you can use the dbms_scheduler.set_attribute procedure to assign an existing job to that class.
Oracle Database 10g offers user-configurable default tablespaces. Use the alter database set default tablespace command to configure this new feature. Once a new default tablespace is configured, all new users will be assigned to that tablespace rather than the SYSTEM tablespace. Here is an example of configuring a default tablespace with the alter database command:
Alter database set default tablespace users;
Oracle Database 10g now allows you to define tablespace groups, which are logical groupings of tablespaces. This further allows you to assign temporary tablespaces