HELP: Split parameter for FLAM4FILES (z/OS only)
TYPE: OVERLAY
SYNTAX: SPLIT.{SIZE=num/NUMBER=num}
During compression a FLAMFILE can be split serially or in parallel into several parts, subject to the settings of the parameters SPLITMODE, SPLITNUMBER, and SPLITSIZE. Only the filename (or DD-name) of the first fragment of a split FLAMFILE must be specified at decompression and no additional settings are required. FLAM detects automatically whether and, if so, how a FLAMFILE has been split and searches by itself for the remaining fragments. Splitting of FLAMFILEs is only available for binary compression modes (MODE=CX8,VR8,ADC,NDC). Binary information has been added to every part of a split FLAMFILE.
Serial splitting (SPLIT.SIZE=nnnn) means that when the file currently used to store compressed data reaches a specified size limit it is closed and subsequent processing stores the compressed data into a newly created file (fragment). The number of fragments of a split FLAMFILE created is not limited. It only depends on the amount of data generated by the compression process. At decompression, FLAM verifies the order, the presence and the affiliation of all fragments.
This feature provides an efficient support for file size limitations (e.g. with e-mail attachments or file transfers). It can also improve system performance by allowing transmission of fragments over a network to begin before termination of the entire compression process.
With parallel splitting (SPLIT.NUMBER=n) compressed data is stored into a specified number of fragments. The current version can handle up to 4 parallel fragments. The size of the fragments depends on the amount of data generated during compression. At decompression, FLAM verifies the order, the presence and the affiliation of all fragments. Decompression requires the accessibility of all fragments of a FLAMFILE. None of the data can be recovered when one parallel fragment is missing.
One benefit of parallel splitting can consist in improved utilization of transmission capacities. Also, locally distributing FLAMFILE fragments may avoid unauthorized decompression without using encryption.
NUMBER: SIZE=num - Size for serial splitting (after 1-4096 in megabytes (only for z/OS)) [100]NUMBER: NUMBER=num - Number for parallel splitting (2-4 files (only for z/OS)) [4]