Extended Compression Architecture
BMC Software Subsystem employs the exclusive BMC Software Extended Compression Architecture (XCA).
XCA is a multiple address space subsystem architecture that follows current architectural trends that are used by IBM.
XCA has the following components:
- BCSS–the XCA control facility that directs the other components
- set of compression techniques--Dynamic Adaptive, Arithmetic Adaptive, Extended Character, Static Huffman, Repeating Character, Hardware, and Custom Dictionary for Hardware
- REGISET–a set of VSAM data sets that contain registration and control information for BMC products
The following table describes the benefits that are provided by XCA.
Benefits of XCA
Benefit | Description |
|---|---|
BCSS services | BCSS provides the following services:
Multiple jobs can use a single CAS; however, the BCSS creates and supports more compression address spaces when needed. |
sharing among products | XCA can be shared among many BMC products. This feature reduces the burden on your system when you have more than one BMC product that uses XCA. |
resource management | XCA provides resource management for itself and the BMC products that use XCA. When a product no longer needs a resource, XCA frees the resource. |
reduced storage requirements | XCA reduces virtual storage requirements in local and CAS compression. If you choose local compression, all compression routines and work areas are located above the 16 MB line at the top of the extended private area. If you choose CAS compression, the compression routines and work areas are isolated in a separate address space. |
downward compatibility | Compression routines are downward compatible with previous releases. When applying changes or enhancements to the compression routines, the new techniques can expand data that was compressed with previously selected techniques. |