Using RCP with Sequential File stages
Runtime column propagation (RCP) allows InfoSphere® DataStage® to be flexible about the columns you define in a job.
If RCP is enabled for a project, you can just define the columns you are interested in using in a job, but ask InfoSphere DataStage to propagate the other columns through the various stages. So such columns can be extracted from the data source and end up on your data target without explicitly being operated on in between.
Sequential files, unlike most other data sources, do not have inherent column definitions, and so InfoSphere DataStage cannot always tell where there are extra columns that need propagating. You can also use Schema File property on Sequential Files when RCP is enabled. Specify a schema in the sequential file which describes all the columns. You need to specify the same schema file for any similar stages in the job where you want to propagate columns. Stages that will require a schema file are:
- Sequential File
- File Set
- External Source
- External Target
- Column Import
- Column Export