Editing Atomic commit (section)

{{Short description|Operation that applies a set of distinct changes as a single operation}}
In the field of [[computer science]], an '''atomic [[Commit (data management)|commit]]''' is an operation that applies a set of distinct changes as a single operation. If the changes are applied, then the atomic commit is said to have succeeded. If there is a failure before the atomic commit can be completed, then all of the changes completed in the atomic commit are reversed. This ensures that the system is always left in a consistent state. The other key property of isolation comes from their nature as [[atomicity (database systems)|atomic]] operations. Isolation ensures that only one atomic commit is processed at a time. The most common uses of atomic commits are in [[database systems]] and [[Version control|version control systems]].

The problem with atomic commits is that they require coordination between multiple systems.<ref>{{cite book |last=Bocchi |first=Wischik |title=A Process Calculus of Atomic Commit |year=2004}}</ref> As computer networks are unreliable services, this means no algorithm can coordinate with all systems as proven in the [[Two Generals' Problem|Two Generals Problem]]. As databases become more and more distributed, this coordination will increase the difficulty of making truly atomic commits.<ref>{{cite book |first1=Hector |last1=Garcia-Molina |first2=Jeff |last2=Ullman |first3=Jennifer |last3=Widom |title=Database Systems The Complete Book |url=https://archive.org/details/databasesystemsc0000_2ndedgarc |url-access=registration |pages=[https://archive.org/details/databasesystemsc0000_2ndedgarc/page/1008 1008]–1009 |publisher=Prentice Hall |year=2009|isbn=9780131873254 }}</ref>