Editing Optimistic concurrency control (section)

===Examples===
* [[MediaWiki]]'s edit pages use OCC.<ref>[[w:Help:Edit conflict|Help:Edit conflict]]<!-- Use interwiki syntax so that mirrors can at least have a chance to pick it up --></ref>
* [[Bugzilla]] uses OCC; [[edit conflict]]s are called "mid-air collisions".<ref>{{cite web | url = https://wiki.mozilla.org/Bugzilla:FAQ#Does_Bugzilla_provide_record_locking_when_there_is_simultaneous_access_to_the_same_bug.3F_Does_the_second_person_get_a_notice_that_the_bug_is_in_use_or_how_are_they_notified.3F | title = Bugzilla: FAQ: Administrative Questions | work = MozillaWiki | date = 11 April 2012}}</ref>
* The [[Ruby on Rails]] framework has an API for OCC.<ref>{{cite web | url = http://api.rubyonrails.org/classes/ActiveRecord/Locking/Optimistic.html | title = Module ActiveRecord::Locking | work = Rails Framework Documentation}}</ref>
* The [[Grails (framework)|Grails]] framework uses OCC in its default conventions.<ref>{{cite web | url = http://grails.org/doc/1.0.x/guide/single.html#5.3.5%20Pessimistic%20and%20Optimistic%20Locking | title = Object Relational Mapping (GORM) | work = Grails Framework Documentation | url-status = dead | archive-url = https://web.archive.org/web/20140815173309/http://grails.org/doc/1.0.x/guide/single.html#5.3.5%20Pessimistic%20and%20Optimistic%20Locking | archive-date = 2014-08-15 }}</ref>
* The [[GT.M]] database engine uses OCC for managing transactions<ref>{{cite web | url = http://tinco.pair.com/bhaskar/gtm/doc/books/pg/UNIX_manual/ch05s17.html | title = Transaction Processing | work = GT.M Programmers Guide UNIX Edition}}</ref> (even single updates are treated as mini-transactions).
* [[Microsoft]]'s [[Entity Framework]] (including Code-First) has built-in support for OCC based on a binary timestamp value.<ref>{{cite web | url = https://learn.microsoft.com/en-us/ef/core/saving/concurrency?tabs=data-annotations#optimistic-concurrency | title = Handling Concurrency Conflicts | work = Entity Framework documentation hub | date = 5 July 2023}}</ref>
* Most [[revision control]] systems support the "merge" model for concurrency, which is OCC.{{cn|date=February 2023}}
* [[Mimer SQL]] is a [[DBMS]] that only implements optimistic concurrency control.<ref>{{cite web | url = https://developer.mimer.com/article/transaction-concurrency-optimistic-concurrency-control/ | title = Transaction Concurrency - Optimistic Concurrency Control | work = Mimer Developers - Features | access-date = 22 Dec 2023}}</ref>
* [[Google App Engine]] data store uses OCC.<ref>{{cite web | url = http://code.google.com/appengine/docs/whatisgoogleappengine.html | title = The Datastore | work = What Is Google App Engine? | date = 27 August 2010}}</ref>
* The [[Apache Solr]] search engine supports OCC via the {{Mono|_version_}} field.<ref>{{cite web|url=https://lucene.apache.org/solr/guide/6_6/updating-parts-of-documents.html|title=Updating Parts of Documents|access-date=2018-06-28}}</ref>
* The [[Elasticsearch]] search engine updates its documents via OCC. Each version of a document is assigned a sequence number, and newer versions receive higher sequence numbers. As changes to a document arrive asynchronously, the software can use the sequence number to avoid overriding a newer version with an old one.<ref>{{cite web | title=Optimistic concurrency control | website=Elastic | url=https://www.elastic.co/guide/en/elasticsearch/reference/current/optimistic-concurrency-control.html | access-date=2024-02-05}}</ref>
* [[CouchDB]] implements OCC through document revisions.<ref>{{cite web | title=Technical Overview | website=Apache CouchDB Documentation | url=https://docs.couchdb.org/en/stable/intro/overview.html | access-date=2024-02-06}}</ref>
* The [[MonetDB]] [[Column-oriented DBMS|column-oriented]] [[database management system]]'s transaction management scheme is based on OCC.<ref>{{cite web | url = http://www.monetdb.org/Documentation/Manuals/SQLreference/Transactions | title = Transactions - MonetDB | date = 16 January 2013}}</ref>
* Most implementations of [[software transactional memory]] use OCC.{{citation needed|reason=Claim initially said optimistic locking, now says OCC, both claims unsourced|date=March 2019}}
* [[Redis]] provides OCC through WATCH command.<ref>{{cite web | url = http://redis.io/topics/transactions | title = Transactions in Redis  }}</ref>
* [[Firebird (database server)|Firebird]] uses [[Multiversion concurrency control|Multi-generational architecture]] as an implementation of OCC for data management.{{citation needed|date = November 2020}}
* [[Amazon DynamoDB|DynamoDB]] uses conditional update as an implementation of OCC.<ref>{{cite web | url = https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/WorkingWithItems.html#WorkingWithItems.ConditionalUpdate| title = Working with Items and Attributes - Conditional Writes| access-date = 2 November 2020}}</ref>
* [[Kubernetes]] uses OCC when updating resources.<ref>{{cite web | url = https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.18/#resource-operations-update | title = API Overview - Resource Operations| access-date = 3 November 2020}}</ref>
* [[YugabyteDB]] is a cloud-native database that primarily uses OCC.<ref>{{Cite web|last=Yugabyte|first=Team|title=Explicit locking {{!}} YugabyteDB Docs|url=https://docs.yugabyte.com/latest/architecture/transactions/explicit-locking/|access-date=2022-01-04|website=docs.yugabyte.com|language=en-us}}</ref>
* [[Firestore]] is a NoSQL database by [[Firebase]] that uses OCC in its transactions.
* [[Apache Iceberg]] uses OCC to update tables and run maintenance operations on them.