Data guard와 Active data guard license
Oracle Enterprise Edition에서 아래 DG 옵션이 무료이다.(11gR2 license 문서에서 나옴)
Oracle Data Guard—Redo Apply
Oracle Data Guard—SQL Apply
Oracle Data Guard—Snapshot Standby
그런데 Active Data guard는 Enterprise Edition 옵션에서 추가 비용을 지불하는 옵션이다.
하여 active data guard가 정확히 무엇을 해야 active data guard를 사용한다고 인식되는지 조금 뒤져보았다.
11g문서는 없었고(있을지도 모르지만 못찾았다)
12c기준으로 링크에서 아래처럼 나와있다.(http://www.oracle.com/technetwork/database/options/active-data-guard/overview/index.html)
Data Guard Architecture Overview
Data Guard provides the management, monitoring, and automation software to create and maintain one or more synchronized copies of a production database to protect Oracle data from failures, disasters, human error, and data corruptions while providing high availability for mission critical applications. Data Guard is included with Oracle Database Enterprise Edition.
Active Data Guard Functionality
Active Data Guard is an option license for Oracle Database Enterprise Edition. Active Data Guard enables advanced capabilities that that extend basic Data Guard functionality. These include:
· Real-Time Query - offload read-only workloads to an up-to-date standby database => 즉 DB read-only 모드로 오픈
· Automatic Block Repair - automatic repair of physical corruption transparent to the user => 예전부터 있던 기능
· Far Sync - zero data loss protection across any distance => 12c new feature이다
· Standby Block Change Tracking - enable incremental backups on an active standby => 예전부터 있던 기능
· Active Data Guard Rolling Upgrade - make it simple to reduce planned downtime => 12c new feature. 단, 10.1.0.3부터 DG sql apply는 db rolling upgrade가 가능하다
· Global Database Services - load balancing and service management across replicated databases. See Global Data Services => 12c new feature이다
· Application Continuity - make outages transparent to users. See Application Continuity => (rac one node도 가능) => Requires the Active Data Guard option or the Real Application Clusters option