RESERVE clause

The RESERVE clause allows the user to specify the number of input/output buffers to be allocated at run time for the files.

The RESERVE clause is not supported for line-sequential files.

If the RESERVE clause is omitted, the number of buffers at run time is taken from the DD statement. If none is specified, the system default is taken.

If the file connector referenced by file-name-1 in the SELECT clause is an external file connector, all file-control entries in the run unit that reference this file connector must have the same value for the integer specified in the RESERVE clause.