Variable length records

The CICS Execution Option requires support for random positioning to any byte offset within an input or output file. Random positioning is easily implemented for fixed length records, because any file offset can be easily converted to a record number and a byte offset from the start of the record; however, it is more difficult for variable length records.

In the CICS Execution Option, variable length records are handled either by copying the data to or from fixed format workspace or by building a table to cross-reference record identifiers to file offsets. You can designate the method to be used by specifying the :W or :P options when using the Input File Override (-I) and Output File Override (-O) execution commands.