Loading Knowledge Modules (LKM)

Loading Knowledge Modules (LKM)

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 1-4 Loading Knowledge Module

Description of "Figure 1-4 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.