Transactions and concurrency

Vocabulaire

English	Sens
transaction/trænˈsækʃn/	A group of database operations treated as one unit with defined commit or rollback behaviour.
atomicity	The transaction property that its changes take effect together or are rolled back together.
consistency	The requirement that a correctly defined transaction preserves database constraints.
isolation/ˌaɪsəˈleɪʃn/	The degree to which concurrent transactions are protected from one another's intermediate effects.
durability	The guarantee that committed changes survive the failures covered by the database's recovery model.
serializability	Equivalence of a concurrent transaction schedule to some serial schedule under the chosen equivalence criterion.
two-phase locking	A locking protocol that permits no new lock acquisition after the first lock release.
isolation levels	Specified concurrency guarantees defining which transaction anomalies are prevented or allowed.