1. A method of maintaining order of a sequence of transactions originating from a source database and being replicated to a target database, comprising: associating a lockable object with each transaction of said sequence of transactions from said source database, each transaction having one or more transactional events, said transactions of said sequence of transactions having an order, said order being a commit order of said transactions in said source database, wherein said lockable object is based on said commit order; attempting to obtain a lock on one or more lockable objects associated with one or more transactions of said sequence of transactions which precede a particular transaction of said sequence of transactions; and in response to being unable to obtain said lock, serially processing said one or more transactional events of said one or more transactions which precede said particular transaction.