The user can control the output medium, memory allocation and OPEN mode (OUTPUT or EXTEND mode). As a standard procedure, SM2U1 output files are opened using OPEN-MODE=*EXTEND.
Similarly to the SM2 output files, restrictions apply to the block length specification. The user must either assign BUFFER-LENGTH=*STD(SIZE=16) or, if the user does not define a block length, the value 16 is assigned by SM2U1. The primary allocation must be at least twice as large and the secondary allocation must be at least the same size as the block length. If these conditions are not met, the primary allocation is set to 32 and the secondary allocation is set to 96.
After the output file or files are closed, PAM pages are released provided the following conditions have been satisfied:
the file is not a dummy file
the pages were already reserved for the file prior to the SM2U1 run
For output files on tapes, it should be considered that due to the extensive checking required, continuous writing to a tape (OPEN-MODE=*EXTEND) may require several time-consuming spooling operations.