When you develop a Lookup transformation, you need to consider factors such as the lookup source type and the lookup condition.
Consider the following factors when you develop a Lookup transformation:
Whether you want to create the transformation from a flat file, logical data object, reference table, or relational data object. Before you create a Lookup transformation, create the lookup source. Import a flat file or relational database table as a physical data object. Or, create a logical data object or reference table to use as a lookup source.
The output ports for the transformation.
The lookup conditions in the transformation.
Whether you want the Integration Service to cache lookup data. The Integration Service can cache data for flat files, reference tables, or relational data objects.