Unlike Parallel Jobs, input or output (passive) stages can be deployed in designs which enable a single stage to act as both an input and output in a Server job. When a job contains such a design, the Server engine will synchronize execution of the stage, so that any load processes are completed before performing the read processes.
For example, consider the following job design:
The processes used by the server job will be synchronized such to ensure that the stages in Group 1 (above) are fully executed before starting the stages in Group 2. To convert this job design to run on the PX engine we’ll need to create a Parallel job representing each of the job’s synchronised sub-groups (1 and 2) and a coordinating sequence to mimic the synchronization provided by the Server Engine:
A similar challenge exists for shared containers that include stages that act as both a source and target. The same principles apply here but need to split the shared containers:
Jobs that use |