When you create a mapping, you create a set of instructions for the Data Integration Service to read data from a source, transform it, and write it to a target. The Data Integration Service transforms data based on dataflow in the mapping, starting at the first transformation in the mapping, and the data type assigned to each port in a mapping.
The Developer tool displays two types of data types:
Native data types
Native data types are specific to the relational table or flat file used as a physical data object. Native data types appear in the physical data object column properties.
Transformation data types
Transformation data types are set of data types that appear in the transformations. They are internal data types based on ANSI SQL-92 generic data types, which the Data Integration Service uses to move data across platforms. Transformation data types appear in all transformations in a mapping.
Transformation data types include the following data types:
Primitive data type. Represents a single data value in a single column position.
Complex data type. Represents multiple data values in a single column position. Use complex data types in mappings that run on the Spark engine to process hierarchical data in complex files.
When the Data Integration Service reads source data, it converts the native data types to the comparable transformation data types before transforming the data. When the Data Integration Service writes to a target, it converts the transformation data types to the comparable native data types.
When you specify a multibyte character set, the data types allocate additional space in the database to store characters of up to three bytes.