An LKM is in charge of loading source data from a remote server to the staging area. It is used by
interfaces when some of the source datastores are not on the same data server as the staging area. The
LKM implements the declarative rules that need to be executed on the source server and retrieves a
single result set that it stores in a “C$” table in the staging area, as illustrated below.
Figure 1: Loading Knowledge Module
1. The LKM creates the “C$” temporary table in the staging area. This table will hold records loaded
from the source server.
2. The LKM obtains a set of pre-transformed records from the source server by executing the
appropriate transformations on the source. Usually, this is done by a single SQL SELECT query
when the source server is an RDBMS. When the source doesn’t have SQL capacities (such as flat
files or applications), the LKM simply reads the source data with the appropriate method (read file
or execute API).
3. The LKM loads the records into the “C$” table of the staging area.
An interface may require several LKMs when it uses datastores from different sources. When all source
datastores are on the same data server as the staging area, no LKM is required.