Data Transformation Engine Introduction to the Design Studio

Chapter 4 - Map Designer Maps and Map Files
Introduction to the Design Studio
41
Maps and Map Files
The Map Designer is used to create and manage maps. Maps are used to retrieve
and validate input data, build output data from input data according to the
mapping rules you have specified, and then deliver the results to the designated
target(s).
The tasks involved in creating and managing map files include:
♦ Creating map source files (.mms).
♦ Creating executable and functional maps in the map source file.
♦ Creating input and output cards for each map.
♦ Building compiled map files (.mmc).
♦ Running maps.
♦ Viewing run results.
♦ Using the trace and audit log files to resolve data transformation or other
mapping issues.
A map source file (
) is used to store maps that are related to each other. A map
source file is a file you create and save using the commands on the File menu in
the Map Designer. A map source file has the file name extension of .mms. The
name of the active map source file and map appear on the Map Designer title bar.
A map source file (.mms) maintains maps in source format. You must build a
compiled map (.mmc) in order to execute it. Maps are not executed directly from
a map source file (.mms), but from a compiled map (.mmc).
A map (
) defines how to generate data objects of a certain type or multiple
independent data objects, each of a certain type. A map contains input and output
cards that transform data content from source formats to target formats according
to rules contained in the map. This data transformation occurs according to
mapping rules on the data objects in the output card in the map.
Input and Output Cards
Input and output cards in a map represent data objects. Each card represents one
data object that is defined as a particular type in a type tree. There are two types
of map cards: input cards and output cards.
♦ An input card (
) contains the complete definition of an input for a map. The
input definition includes information such as source identification, retrieval
specifics, and the behavior that should occur during processing.