Data Quality

] ~ ~ C H A P T E R

9 Structure Analysis

Another common source of structural flaws occurs when extracting data

from structures that support REDEFINE and OCCURS structures. The

extraction designer needs to understand the semantic meaning of these struc-

tures in order to extract properly. For example, the REDEFINE must be

understood to be a remapping of either the same fact or different facts,

depending on the value of some other column. Similarly, the OCCURS struc-

ture must be understood to be either the same fact with multiple occurrences

or multiple different facts. Failure to understand ...