The adapter is extremely efficient because:

1. IDMS data sources are not physically recreated as FOCUS data sources in order to make them intelligible to FOCUS. Only Master and Access Files are required to describe the IDMS data source to FOCUS.
2. End users can access IDMS data sources easily with FOCUS requests. No 3GL programming is required.
3. IDMS resources used to access records are kept to a minimum because the adapter:
   • Readies only those IDMS areas needed for report generation.
   • Binds and accesses only the records needed to obtain report data.
   • Minimizes IDMS I/O by creating optimal DML and LRF calls based on the available selection criteria (IF and WHERE criteria).
   • Minimizes IDMS I/O based on a user-specified point of entry (alternate file view).