Database Systems - Distributed Transaction In 2-phase commit (2PC) scheme, a resource manager (RM) needs to force write a certain log record on two occasions during the commit process, as shown in the diagram below. Are they strictly necessary? Discuss the consequences that may entail if either of the force write is replaced by an asynchronous write-

TM and its log	message	participating DBMS and its log
	Prepare
		Prepare*/Abort*
	Vote Yes/No
Commit*/Abort*
	Commit/Abort
		Commit*/Abort*
	ACK
end