DB2 9 vs Oracle 10g Admin. Technology - IBM

DB2 Information ManagementMVRC 와 ANSI 분리 레벨실상황예제첫번째 예제: MVRC두번째 예제: MVRC force serializingDB2와 유사Transaction 1Transaction 2Transaction 1Transaction 2Begin Transaction.Begin Transaction.Begin TransactionBegin TransactionSELECT available seatsfrom flight ABC111.See seat 23F is lastavailable.Reserve seat.SELECT available seats fromflight ABC111 using FORUPDATE clause.See seat 23F is last available.Reserve seat.SELECT available seats onflight ABC111.SELECT available seats on flightABC111 using FOR UPDATE.Also see 23F available as Oraclegoes to rollback segment to getthe old version of that block.Blocks wait on lock from firsttransaction.Commit Transaction.Commit Transaction.Reserve seat.Commit TransactionSELECT returns with no seatsavailable.Successful Commit with lostupdate.Book on another flight.Flight is oversold!DB2 9 vs Oracle 10g© 2008 IBM Corporation 97