When you configure a data object read operation for the Teradata data object and view it in the object editor, you can see a source object and an output object. The output object displays the metadata from the Teradata resource.

The following image shows a data object read operation for the Teradata data object:

The source object is

tpt_src

and the output object is

Output

. The source and output objects comprise the data object read operation.

You can look at the metadata in the output object and see that the native data types in

tpt_src

are converted into transformation data types in the output object. For example, the native data type VARCHAR for the

name

port is converted to the transformation data type string.

To use the Teradata data object in a mapping, you can create a Read transformation. When you add the Read transformation to the mapping, you select the Teradata data object and the data object read operation that you previously configured.

Because the Read transformation needs to access the transformation data types stored in the output object of the data object read operation, the Read transformation is created based on the object operation, not the Teradata data object. The Read transformation uses the same properties that you configured for the data object read operation.

The following image highlights the Read transformation

tpt_read

in the mapping editor:

Notice that the metadata in the Read transformation and the output object of the data object read operation are the same. For example, the metadata in the

name

port uses the transformation data type string instead of the native data type VARCHAR.