To access feature type format parameters, open the Feature Type Properties dialog by clicking the properties 
button on a feature type in the workspace.
These parameters apply only to a selected feature type, not to the entire reader.
Note: If a feature type parameter corresponds to a reader-level parameter, then the reader parameter will be ignored and the feature type parameter will be used.
Raster Column
The name of the field containing raster data when reading from only one of multiple raster columns. When not specified, the first raster column found is chosen.