To link data between source and target databases, you must establish data correspondence between the source and target databases that use the update information. Information about the source database is called the extraction definition, while information about the target database is called the import definition.

You must specify these definitions for the data linkage product (Datareplicator or XDM/DS). When you use a SAM file in linking data, you must specify the mainframe database definitions before you create the dataset to be transferred to the file transfer program.

You use the extraction definition to establish the correspondence between the source database and the update information, and you use the import definition to establish the correspondence between the update information and the target database. The update information consists of mapping keys that identify specific rows with specific update data. The following figure shows the correspondence between the source and target databases.

Figure 1-7 Correspondence between the source and target databases

#

This example assumes that a HiRDB is the source database.