Schemas

Schemas are an alternative way for you to specify column definitions for the data used by parallel jobs.

By default, most parallel job stages take their meta data from the Columns tab, which contains table definitions, supplemented, where necessary by format information from the Format tab. For some stages, you can specify a property that causes the stage to take its meta data from the specified schema file instead. Some stages also allow you to specify a partial schema. This allows you to describe only those columns that a particular stage is processing and ignore the rest.

The schema file is a plain text file, this appendix describes its format. A partial schema has the same format.

Note: If you are using a schema file on an NLS system, the schema file needs to be in UTF-8 format. It is, however, easy to convert text files between two different maps with a InfoSphere® DataStage® job. Such a job would read data from a text file using a Sequential File stage and specifying the appropriate character set on theNLS Map page. It would write the data to another file using a Sequential File stage, specifying the UTF-8 map on the NLS Map page.