In order to ensure that ALL internal relationships are accurately defined, textual ETL has
to have verification processing executed before textual ETL can be run.

Fig. 10.1.22 shows the need for verification processing.

Fig. 10.1.22 Verification processing.

If any one or more internal relationship is found to be out of place or not defined, the
verification process sends a message identifying the relationship that is out of order and
declares that the verification process has not been properly passed.

Preprocessing, Postprocessing

There is a lot of complexity to the processing inside textual ETL. In most cases, a
document can be processed entirely within the confines of textual ETL. However, on
occasions, it is possible to either preprocess a document or postprocess the document (or
do both) if necessary.

Fig. 10.1.23 shows that textual ETL can have either or both preprocessing or
postprocessing.

Chapter 10.1: Nonrepetitive Data