It receives
input from the source, transforms it according to the type of transformation required
and generates an output or outputs that will be written to the destination. It may
also generate error output(s) that will be ported to other destination(s) as shown
in the following schematic diagram. Although just one transformation is shown
in the diagram, there could be a number of transformation stages (a chain of
transformations) before the data reaches the destination.
A brief explanation of what each of these data flow transformations contribute to
package design is given in the following sections:
Aggregate
Aggregate functions used in the SQL syntax such as SUM, AVERAGE, etc. are provided
by this transformation. This transformation can either provides a value, or a warning,
that can be used in another process. The processing is carried out asynchronously on
the data. It can also be used in formulating SQL syntax using the GROUP BY clause.
will find an example in Chapter 9.
Audit
This transformation supports inclusion of environment information into the package
in which it is used. This enables auditing the package. This has only one input and
one output. Audit information is added to the data flow information.
Chapter 1
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Character Map
This transformation takes care of string transformations. A string in a column can
be replaced, or a new column can be added with replaced strings. For example, first
name, last name, etc.
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