The generation of EDBI routines is based on the extended file description (EFD) generated by the Compiler.

If you generate the EDBI routines in one step at compile time, the EFD is kept in memory and you don’t have to care about it.

If you choose to generate the EDBI routines using EDBIIS, instead, you need to save the EFD to disc and this is achieved through the -efd compiler option.