This macro defines the data control block (DCB) for an extrapartition transient data destination.
You must also code a DFHDCT TYPE=EXTRA macro, to define the destination.
Extrapartition data sets can be blocked or unblocked, of fixed or variable length.
>>-DFHDCT--TYPE=SDSCI--,DSCNAME=name--+-----------------+-------> '-,BLKSIZE=length-' >--+---------------------+--+----------------------+------------> | .-1------. | | .-IGNORE-. | '-,BUFNO=--+--------+-' '-,ERROPT=--+--------+-' '-number-' '-SKIP---' >--+------------------------+--+-----------------+--------------> '-,RECFORM=--+-FIXUNB--+-' '-,RECSIZE=length-' +-FIXUNBA-+ +-FIXUNBM-+ +-FIXBLK--+ +-FIXBLKA-+ +-FIXBLKM-+ +-VARBLK--+ +-VARBLKA-+ +-VARBLKM-+ +-VARUNB--+ +-VARUNBA-+ '-VARUNBM-' >--+----------------------+--+-----------------------+--------->< '-,REWIND=--+-LEAVE--+-' | .-INPUT--. | '-REREAD-' '-,TYPEFLE=--+--------+-' +-OUTPUT-+ '-RDBACK-'
For V format data sets, each block consists of a block descriptor word followed by one or more logical records. The value coded for BLKSIZE must include 4 bytes for the block descriptor word, and also make allowance for the largest possible logical record (which itself includes 4 bytes of record descriptor word).
If the data set already exists, BLKSIZE can be omitted. However, if BLKSIZE is coded for an input data set it should match the data set BLKSIZE.
The name used for DSCNAME must be used as the ddname on the DD statement, and is also used as the name for the DCB that is created.
The name must not start with the letters “DFH”, which are reserved for use by CICS®, unless it is describing one of the standard destinations. Use of the prefix “DFH” may cause assembly errors and future compatibility problems, because the DSCNAME parameter becomes an externally-specified name.
For V format data sets, each logical record consists of a record descriptor word followed by a data record. The value coded for RECSIZE must include 4 bytes for the record descriptor word (or LLBB), and also make allowance for the largest possible data record.
RECSIZE=length need be coded only for RECFM=FIXBLK.
An extrapartition SDSCI can be either input or output, but not both.
For more information on the above operands, see MVS/ESA Data Administration: Macro Instruction Reference.