In
database systems, durability is the
ACID
In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a sequ ...
property which guarantees that
transaction
Transaction or transactional may refer to:
Commerce
* Financial transaction, an agreement, communication, or movement carried out between a buyer and a seller to exchange an asset for payment
*Debits and credits in a Double-entry bookkeeping sys ...
s that have committed will survive permanently.
For example, if a flight booking reports that a seat has successfully been booked, then the seat will remain booked even if the system crashes.
Durability can be achieved by flushing the transaction's log records to
non-volatile storage before acknowledging commitment.
In
distributed transactions, all participating servers must coordinate before commit can be acknowledged. This is usually done by a
two-phase commit protocol.
Many DBMSs implement durability by writing transactions into a
transaction log that can be reprocessed to recreate the system state right before any later failure. A transaction is deemed committed only after it is entered in the log.
See also
*
Atomicity
*
Consistency
*
Isolation
*
Relational database management system
A relational database is a (most commonly digital) database based on the relational model of data, as proposed by E. F. Codd in 1970. A system used to maintain relational databases is a relational database management system (RDBMS). Many relatio ...
References
Data management
Transaction processing
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