When you issue a FOCUS report request, the adapter analyzes the requirements specified in the request and sets up retrieval procedures to efficiently locate and retrieve the data records that fulfill those requirements. Depending on the specific request, the adapter automatically generates optimized DL/I calls.

The adapter retrieves from the IMS DBMS only those records corresponding to the fields referenced in the report request. Additionally, the adapter may instruct the IMS DBMS to apply the record selection criteria specified in the request, freeing FOCUS from this task. This optimization technique reduces the volume of DBMS-to-FOCUS communication, resulting in faster response times for adapter users. FOCUS can then join, sort, and aggregate data as necessary.