When installing CA Compress for IMS, if the intension is to only use database compression but not the interactive dialog, does an authorized user still need to be defined?
An authorized user is required only for the CA Compress for IMS Interactive Dialog which is the ISPF interface for Compress. If you do not wish to use the Interactive Dialog then you can still execute Compress or Express. This is fully covered in the CA Compress for IMS User Guide, chapter - Database Compression without the Interactive Dialog.
IMEXPRES has the added advantage that it does not require FDTs and therefore does not require a SEGCC macro. This is a non-customized compression and provides the easiest implementation of compression.