CA IDMS Environment › Overview › Multiuser Environment

Multiuser Environment

Central Version

In a multiuser environment, you use the services of the CA IDMS/DC or CA IDMS UCF central version to access the database. When two or more users attempt to access or update the database simultaneously, the DBMS, which is part of the DC/UCF system, controls and coordinates access to the database.

Central version operations provide greater concurrency and recovery services than local mode operations.

Under central version:

• The DBMS ensures the integrity of the database by controlling concurrent access through locks placed on areas and table rows or record occurrences.
• The DBMS performs automatic recovery operations for programs that end abnormally

Requesting Central Version Services

Application programs executing within the following environments can make database requests of the central version:

• Batch address spaces
• CA IDMS/DC and CA IDMS UCF (DC/UCF) systems
• Other teleprocessing monitors

An application program executing within the DC/UCF environment can take advantage of the single region architecture of CA IDMS. Because the database and data communications services operate within a single address space, database requests do not need to be transferred across address spaces.