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11g新特性:Rolling Upgrade With Physical Standby

作者: Maclean Liu, post on March 26th, 2011

从Oracle 10.1.0.3开始引入了利用逻辑备库(logical standby)实施滚动升级(rolling upgrade)的特性；在滚动升级期间(rolling upgrade)，允许主库(primary database)与逻辑备库(logical standby)间运行不同的数据库版本，以最小化宕机时间。

到了11g中增加了可以将物理备库(physical standby)临时性转换成逻辑备库(logical standby)以完成滚动升级，之后将该临时逻辑备库反转为物理备库的功能。使用以上临时转换功能只需要在转换语句”ALTER DATABASE RECOVER TO LOGICAL STANDBY”后加上”KEEP IDENTITY”选项。除去转换细节的区别外，使用物理备库进行滚动升级的过程与10g中的逻辑备库滚动升级没有太大的区别。

这里我们通过实验来亲身体验一下这一新特性，我们假设环境中存在一套11.1.0.7的Data Guard系统：

Database Role DB_UNIQUE_NAME Version Primary Database PROD 11.1.0.7 Physical Standby SBDB2 11.1.0.7

当前的需求是将生产数据库升级到11.2.0.2，但要求最小化应用downtime；这里我们就可以充分利用Data Guard的环境借势升级，同时也不会破坏原有的HA可用性：

1.滚动升级前需要为Primary Database做必要的准备工作，这里如果数据库之前没有启用闪回数据库的话需要enable SQL> SHUTDOWN IMMEDIATE; SQL> STARTUP MOUNT; SQL> ALTER DATABASE FLASHBACK ON; SQL> select flashback_on from v$database; FLASHBACK_ON —————— YES SQL> . . . → Read More: 11g新特性:Rolling Upgrade With Physical Standby

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Recreate failovered primary database using Flashback Database

作者: Maclean Liu, post on February 24th, 2011

很多朋友一直对DataGuard的fast-start failover持怀疑的态度;通过observer的观察，(Fast-Start Failover)FSFO提供了一种在primary数据库不可用情况下自动故障切换到standby数据库的能力。造成很多朋友不愿意使用FSFO的原因之一是故障切换后不得不重建原primary数据库，不过如果我们能配合使用10g中的闪回数据库特性的话，这一重建数据库的工作便也可以一劳永逸了。

/* 启用fast_start failover的前提之一是在primary和standby库上都启用flashback database */ SQL> select * from v$version; BANNER ——————————————————————————– Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 – 64bit Production PL/SQL Release 11.2.0.2.0 – Production CORE 11.2.0.2.0 Production TNS for Linux: Version 11.2.0.2.0 – Production NLSRTL Version 11.2.0.2.0 – Production /* 当前的primary库情况 */ SQL> select open_mode ,database_role,flashback_on from v$database; OPEN_MODE . . . → Read More: Recreate failovered primary database using Flashback Database

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Rolling a Standby Forward using an RMAN Incremental Backup

作者: Maclean Liu, post on December 19th, 2010

Rolling a Standby Forward using an RMAN Incremental Backup in 9i

Purpose

This document describes a method of rolling forward a standby database using incremental backups (instead of the typical media recovery process MRP).  The process uses an RMAN incremental backup taken on the primary database which is then applied to the standby database.

Introduction . . . → Read More: Rolling a Standby Forward using an RMAN Incremental Backup

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Oracle Active Data Guard-Technical Overview

作者: Maclean Liu, post on December 19th, 2010

Historical – but still found with surprising frequency in IT shops even today.

Active-Passive model – impossible to scale-out, many systems underutilized.

HA components are not application aware. Difficult or impossible to provide optimal data protection and availability because third party components are not able to take advantage of native features of a given application.

. . . → Read More: Oracle Active Data Guard-Technical Overview

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Improved features to Deploy PeopleSoft on Oracle Grid

作者: Maclean Liu, post on December 17th, 2010

PeopleSoft new Features on the Grid Support for PeopleSoft Application Continuity Transparent Application Failover Fast Application Notification Active Data Guard support Workload Tagging Module, Action, Client and Service Information PeopleSoft Consumer Groups Support for Advanced Compression & Partitioning Oracle Grid new features RAC One Node & Instance Caging Single Instance RAC Database Cold Failover Limit . . . → Read More: Improved features to Deploy PeopleSoft on Oracle Grid

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Best Practices for Automatic Failover Using Oracle Data Guard 10g Release 2

作者: Maclean Liu, post on November 26th, 2010

Agenda Fast-Start Failover Overview Fast-Start Failover, Details & Best Practices Failover Processing Flow Failover Events and Monitoring Best Practices Test Results Automatic Client Failover Questions? Failover Requirements Faster is better Downtime is bad If manual intervention is required, the time it takes to notify administrative staff can be lengthy Reliability is a must-have Correct procedure . . . → Read More: Best Practices for Automatic Failover Using Oracle Data Guard 10g Release 2

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Make Money with Active Data Guard

作者: Maclean Liu, post on November 18th, 2010

Active Data Guard with Oracle Database 11g creates entirely new opportunities for I.T organizations that extend far beyond disaster recovery.

This presentation discusses how Active Data Guard, a new database option available with Oracle Database 11g will help I.T. organizations meet the challenge of enhancing the Quality of Service offered to their customers while at . . . → Read More: Make Money with Active Data Guard

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ARCHIVER ERROR ORA-00354: CORRUPT REDO LOG BLOCK HEADER

作者: Maclean Liu, post on November 6th, 2010

Problem Description: ORA-16038: log 2 sequence# 13831 cannot be archived ORA-00354: corrupt redo log block header ORA-00312: online log 2 thread 1: ‘/oradata/3/TOOLS/stdby_redo/srl1.log’

LOG FILE ————— Filename = alert_TOOLS5_from_1021.log See … … Wed Oct 28 11:41:59 2009 Primary database is in MAXIMUM AVAILABILITY mode Standby controlfile consistent with primary RFS[1]: Successfully opened standby log 1: . . . → Read More: ARCHIVER ERROR ORA-00354: CORRUPT REDO LOG BLOCK HEADER

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