DCB parameter

Parameter Type

Keyword, optional

Purpose

Use the DCB parameter to complete during execution the data set information in the data control block (DCB).

The data control block is constructed by the DCB macro instruction in assembler language programs or by file definition statements or language-defined defaults in programs in other languages.

Note:

With SMS, you do not need to use the DCB parameter to specify data set attributes. See the DATACLAS parameter (described on section DATACLAS parameter), the LIKE parameter (described on section LIKE parameter), and the REFDD parameter (described on section REFDD parameter).
For JES3 SNA RJP, code DCB=LRECL=nnn; where nnn is 1 to 255 when SYSIN data records are greater than 80 bytes. (The default LRECL is 80 bytes.)
Cross checking of DCB subparameters is done when the data set is opened, not when it is allocated. It is therefore possible to create a data set which may not be usable. This may then result in the issuance of a system completion code (ABEND) or unpredictable results when the data set is opened.

References

For more information on constructing the data control block, see z/OS DFSMS Using Data Sets.