A Survey on Operational Transformation Algorithms: Challenges, Issues and Achievements 1 <s> GOT <s> Rd-time group editors dow a group of users to view and edit, the same document at the same time horn geograpbicdy di.~ersed sites connected by communication networks. Consistency maintenance is one of the most si@cant &alwiges in the design and implementation of thwe types of systems. R=earch on rd-time group editors in the past decade has invented au inuolative tetique for consistency maintenance, ded operational transformation This paper presents an integrative review of the evolution of operational tra=formation techniques, with the go~ of identifying the major is-m~s, dgotiths, achievements, and remaining Mlenges. In addition, this paper contribut= a new optimized generic operational transformation control algorithm. Ke~vords Consistency maint enauce, operational transformation, convergence, CauS*ty pras~ation, intention pre~tion, group e&tors, groupware, distributed computing. <s> BIB001 </s> A Survey on Operational Transformation Algorithms: Challenges, Issues and Achievements 1 <s> GOT <s> Traditional concurrency control methods such as locking and serialization are not suitable for distributed interactive applications that demand fast local response. Operational transformation (OT) is the standard solution to concurrency control and consistency maintenance in group editors, an important class of interactive groupware applications. It generally trades consistency for local responsiveness, because human users can often tolerate temporary inconsistencies but do not like their interactions be lost or nondeterministically blocked. This paper presents a time interval based operational transformation algorithm (TIBOT) that overcomes the various limitations of previous related work. Our approach guarantees content convergence and is significantly more simple and efficient than existing approaches. This is achieved in a pure replicated architecture by using a linear clock and by posing some constraints on communication that are reasonable for the application domain. <s> BIB002
Although IT and ET functions defined in GOT BIB001 do not use explicit extra parameters, they use extra internal data structures to save information that helps break ties in some cases. are proposed to free TP2 by maintaining the same transformation path (total order of operations) at all sites every time an operation o is transformed. Although these algorithms can converge, those approaches are not always able to preserve the correct object order because they cannot prevent the loss of landmark characters in their transformation paths, without requiring TP1 and TP2, the GOT control algorithm, integrated with the undo/ do /redo scheme BIB002 , is the only known solution for achieving both intention-preservation and convergence..