For the MEL check MEL-Mi-22-70-02.
Thats what my A320 MEL says:
One may be inoperative or out of date provided that:
1)
The operative database must be up to date for routes, departures, arrival and approach procedures that require the use of Navigation Database for RNAV/RNP, and
2)
The operative database is available and used by the flight crew member(s) responsible for navigation, and
3)
Radio navigation aids, which are required to be flown for departure, arrival and approach procedures are manually tuned and identified.
Ther is an operational procedure attached to that, that quite clearly states that RNP 4 and RNAV 10 operations are not permitted in that case.
If both are out of date or inop one has to check for every used RNAV/RNP procedure way point used that there haven't been any changes from the installed database to the current AIRAC cycle.