Things to consider when using EXECIO
- Enclose EXECIO Commands within quotation marks to prevent erroneous substitution of variables, especially if processing via the use of variables.
- On z/OS read for update (DISKRU) does not support spanned record data sets. (Spanned records are those which are greater in size than the BLKSIZE and hence span multiple blocks.)
- If using update inplace (DISKRU) on z/OS the replacement record must be the same size as the record being replaced.
- On z/OS if a data set has been allocated with Track Overflow it is likely that message IEC137I will be issued by DFSMS.
- On z/OS the data set must be either sequential or a member of a PDS or PDSE. VSAM ESDS, KSDS, RRDS and LDS data sets are not supported
- On z/OS only one member of a PDS(E) should be open at a time
- On z/OS the data set must be allocated, either via TSO ALLOC, JCL DD statement, or some other Dynamic method.
- On z/VM the file to be process must be available on the current mini-disk configuration.
- On z/OS multiple user system data sets should be allocated with a disposition of OLD to guarantee exclusive use.
- On both z/OS and z/VM, the file or data set is left open by default, i.e. there is no implicit close.