{HEAD ~ A multi tenant database} may be split between {TAIL ~ two or more databases} while the database being split continues processing requests 
{ HEAD ~ A multi tenant database } may be split between { TAIL ~ two or more databases } while the database being split continues processing requests
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH