The Compare Layouts– Copybook window lets you check that the calculated association is correct, by checking the byte-by-byte congruence of the data element layout with an associated copybook.
Data Express uses an association algorithm to determine the list of compatible copybooks (that describe its trace) for each data store. The association algorithm is based on:
The information for copybook bytes is obtained from the analysis of the source of the same copybook. The information for file bytes is obtained during the file analysis on the basis of the congruence of the values found within the records, their positions being equal.
Each byte, depending on its type, has a specific hexadecimal content. The evaluation of the congruence between the copybook and the file bytes is based on an algorithm comparing the copybook byte with the hexadecimal content of the corresponding file byte.
To access this function, click (Compare Layouts – Copybook) from the Work with Data Store area.