Release 2Release 3Base ReleaseIntroducing Oracle 11gR2 Edition Based RedefinitionOn Parallel Application UniversesLucas Jellema (Oracle ACE Director)CTO, AMIS

AvailabilityAvailability = Performance * (Up or Down)Up = !DownDown = Unplanned Down + Planned DownPlanned Down???System MaintenancePower-supply, Hardware & Network, O/S upgradeDatabase patching & UpgradeApplication Upgrades

Application UpgradeCreation of new objectsChanging existing objects (alter and create or replace)Add, Modify or Drop columns or constraintsChange packages and stored proceduresRecompileDrop redundant objectsConvert or migrate dataResume normal operationsApplication is DOWN

Compare with road maintenance

Restructuring A12Build new road next to current one (A12-B)Same “functionality” as the old roadAt the cut-over momentOpen new A12-B: Newly arriving traffic travels on temporary roadClose A12 (original)Cars already on old road keep going

Edition Based Redefinition is similarApplication Upgrade:Prepare new releaseConstruct the release in parallel to the existingOperations in existing application ‘edition’ continue normallyFrom the cut-over point:Have new sessions operate on new releaseExisting sessions can continue to run on existing release

Edition Based Redefinition brings a new dimension to the databaseRelease 3Release 2Base Release

Editions introduce or inherit versions of objectsRelease 2Release 3Base Release

Editions are parallel universesDatabase Objects are identified byObject TypeSchemaObject Name…. Edition!(release, application version, stripe, parallel universe id)Database Sessions run in the context of a specific edition Using a specific collection of versions of objects

Database sessions run in a specific edition –one version of each objectRelease 2Release 3Base ReleaseThe database as seen by a sessionrunning in the context of Release 3323B22332

Demo of Application UpgradeExisting base application, in base editionCreate new editon – release_2Create and Alter database objectsBase application continues runningCut-over pointNew sessions run in release_2 editionCurrent sessions continue in base

Some Rules for EBR (Edition Based Redefinition)Editioning acts on packages, functions, triggers, procedures, views, types and synonymsEditioning does not apply to tablesData is not versionend, cloned, migratedDifferent incarnations of a table are suggested through editionable views – there is only one tableApplications should never access tables directly!Cross Edition Triggers on the table synchronize DML from different editions with the current state of the table CET are temporary objects – not part of the application

But wait, there is moreAfter the release of a new edition – there is no reason why you cannot keep the previous one going for some timeAnd multiple previous ones!That means – END OF THE BIG BANG upgrade!Multiple versions of the application can continue running to suport various user groups (e.g. SaaS)Without data migration and additional downtime upon later move over of user groups

Parallel Application VersionsApplication XVERSION 1Application XVERSION 2Release 2Release 3Base Release

Version 1 on Base Edition

Version 1 on Edition Release 2

Upgrade Base to Release 2AuthorsNew columns COUNTRY and BIOGRAPHYBooksDrop column NUM_OF_PAGESModified column ISBN (10 to 20 characters)New columns LANGUAGE and PUBLICATION_YEAR

Version 2 (on Edition Release 2)

Version 2 on Base Edition

SummaryEdition Based Redefiniton11gR2 Editions are parallel, co-existing universes with incarnations of database objectsThe new release can be constructed, tested and run in a new editionThe old edition can be switched off at cut-over Editions also allow long time co-existence of multiple releases of an applicationApplication Upgrade no longer needs to disrupt the operation through planned downtime

ConclusionSee http://www.amis.nlTo do an 11gR2 PoC together with usTo learn about 11gR2 training (DBA & Developer)For more on database migration servicesFree Event: 29th September – technical details on 11gR2 including hands-on sessionSee Blog for 11gR2 articles http://technology.amis.nl/blogContact me: lucas.jellema@amis.nl