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Chapter 5
reference numbers within the braces and expand upon the mapping rules in
hyperlinked supporting documentation or footnotes. If there are conflicting
sources for the same data, slash (/) delimit the choices. As well as identifying
column sources you should also record their data type and length using the codes
in tables 5-1.
Figure 5-2
Dimension table
annotated with
data sources and
profiling results
Place data source references on new rows in the table header and column type (as
in Figure 5-2) so they can be hidden when not needed; e.g., during a model review,
if the source names are not meaningful to the stakeholders.
Table 5-1
Data type codes
C ODE D ATA T YPE
C(n) Character( length )
DT Date and Time
D Date
N(n.n) Numeric( digits, precision )
T Text. Long character data used to hold free format text
B Blob. Binary object used to hold documents, images, sound etc.