CA-L-Serv › Maintain Managed Files › Compress Files

Compress Files

When compressing a managed CA-L-Serv file, CA-L-Serv performs the equivalent of the backup, reset, and restore operations in one step. CA-L-Serv backs up the managed file to a sequential file, deletes the contents of the managed file, and then copies data from the sequential file to the managed file. The compression process:

• Backs up and restores the file without allowing it to be changed between operations. When CA-L-Serv compresses the file, it holds the file exclusively until the backup, reset, and restore operations have completed. Do not specify a DD statement for managed data sets in the LDMAMS JCL.
• Causes the data to be reorganized more efficiently. Compression eliminates VSAM control interval and control area splits; however, it does not automatically release secondary extents.