In IBM's OS/390 operating system, an enclave is a representation of a business transaction or unit of work. Each individual enclave that is active in an address space is assigned a unique dispatching and input/output (I/O) priority, which is determined by the goals the user assigns to the enclave. The OS/390 workload manager then allocates resources to each enclave based on its priority. If several transactions are concurrently sharing the same address space, the less important transactions are deferred until resources needed by the more important transactions become available.

Transaction managers such as DB2 V4 Distributed Data Facility (DDF), DB2 V5 Stored Procedures, IBM HTTP Server for OS/390, and MQSeries Workflow use enclaves.

This was last updated in November 2005

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