Because the manner in which a job is implemented may depend on the platform, each agent keeps its own set of job scripts. Some DBA jobs involve more than one task. For example, before making schema changes to a database, you may want to back up the database. To accommodate these types of jobs, the Job Scheduling System allows you to combine two or more predefined jobs into one composite job . Each of the predefined jobs contained in the composite job is called a task.
Composite jobs can contain test conditions based on the success of a task.
For example, if a composite job consists of two tasks, starting up a database and then running a SQL script, you can specify that the script be run only if the database was successfully started. The Job Scheduling System allows you to run jobs efficiently on multiple remote nodes. When you submit a job to run on a remote node, all the information needed to run the job is transferred to the agent servicing the node. When the job is executed, it is run by the agent on that node, minimizing network traffic between the remote node and the Console and daemon. The only communication between the agents and the Console and daemon are the initial transmission of job information and any subsequent messages about job status changes.