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Atomicity does not behave completely orthogonally with regard to the other ACID properties of transactions. For example, isolation relies on atomicity to roll back the enclosing transaction in the event of an isolation violation such as a deadlock; consistency also relies on atomicity to roll back the enclosing transaction in the event of a consistency violation by an illegal transaction.
An atomic system must guarantee atomicity in each and every situation, including power failures, errors, and crashes. [4] A guarantee of atomicity prevents updates to the database from occurring only partially, which can cause greater problems than rejecting the whole series outright.
In computer science, write-ahead logging (WAL) is a family of techniques for providing atomicity and durability (two of the ACID properties) in database systems. [1]A write ahead log is an append-only auxiliary disk-resident structure used for crash and transaction recovery.
In computer science, shadow paging is a technique for providing atomicity and durability (two of the ACID properties) in database systems. A page in this context refers to a unit of physical storage (probably on a hard disk), typically of the order of 1 to 64 KiB. Shadow paging is a copy-on-write technique for avoiding in-place updates of pages.
There exist several mechanisms to store and reconstruct the state of a database system that improves the performance, both in terms of space and time, compared to managing all the log files created from the beginning of the database system. These mechanisms often include incremental dumping, differential files, and checkpoints. [12]
A transaction manager is middleware which sits between an app service (back-end application service) and the operating system. A transaction manager can provide global isolation and atomicity. It tracks when new servers join a transaction and coordinates an atomic commit protocol among the servers.
In the case of an aborted transaction, it's possible to traverse the log file in reverse order using the Previous Sequence Numbers, undoing all actions taken within the specific transaction. Every transaction implicitly begins with the first "Update" type of entry for the given Transaction ID, and is committed with "End Of Log" (EOL) entry for ...
OLTP is carried in a client-server system. Online transaction process concerns about concurrency and atomicity. Concurrency controls guarantee that two users accessing the same data in the database system will not be able to change that data or the user has to wait until the other user has finished processing, before changing that piece of data.