During ZDU there are often entries in the MQMEM table that are blocking step 6 of the ZDU.
These entries represent processes have been temporarily paused and are therefore written to MQMEM. When an entry was written by a WP of the base version, it also needs to be further processed by a WP of the base version to move forward.
First of all, it is not recommended to just delete these entries in a Production system, because it can impact running jobs.
It is recommended to leave the system in step 6 of the ZDU for some time (1-2 hour or even overnight), this way entries will naturally disappear.
If it is not possible to wait or entries remain even after waiting for some time, you have to manually check them: the remaining entries often contain a runID that can be checked against the Activities. If the RunID corresponds to an job or event that can be skipped, you can stop it and the corresponding entry will be removed from MQMEM.
In addition, the following SELECT returns all MQMEM entries that include RunIDs, but are NOT listed in the Process Monitoring of any client. Those entries CAN be deleted by selecting them in the AWI and deleting them manually:
SELECT MQMEM_PK, MQMEM_SYSTEM, MQMEM_TITLE, MQMEM_MQSET
WHERE MQMEM_PK NOT IN (
FROM MQMEM, EH
WHERE SUBSTR(MQMEM_TITLE, 36, 7) = 'AH_IDNR'
AND EH_AH_IDNR = SUBSTR(MQMEM_TITLE, 44, 10)
Also, entries without a RunID are most likely of type XEXECUTE and can be deleted manually from AWI, if no user is logged into the base version anymore.
XEXECUTE stands for "XRequest execution" and indicates a user interaction via the UserInterface (RichUI or AWI). Those are probably requests that were not executed at all and got stuck in the database. (This may happen, if the user closes the UI (or session), the server crashed, was shut down or a deadlock occurred.)