1 Oracle Data Guard: Overview

1 Copyright © 2006, Oracle. All rights reserved. Oracle Data Guard: Overview Copyright © 2006, Oracle. All rights reserved. 1 - 2 Objectives After completing this lesson, you should be able to do the following: • Describe the factors that affect planned and unplanned downtime • Describe the basic components of Oracle Data Guard • Explain the differences between physical and logical standby databases • Explain the benefits of creating a Data Guard environment • Explain the use of Data Guard in high-availability architectures Copyright © 2006, Oracle. All rights reserved. 1 - 3 Causes of Data Loss Source: Disaster Recovery Journal Natural disasters 3% Software corruption 4% Computer viruses 7% Human errors 36% Hardware & system errors 49% Copyright © 2006, Oracle. All rights reserved. 1 - 4 Understanding the Causes of Downtime Planned downtime Unplanned downtime System changes Data changes Data failures Computer failures Corruption Human error Site failure Storage failure Copyright © 2006, Oracle. All rights reserved. 1 - 5 What Is Oracle Data Guard? Primary database Standby database Database Database copy Redo transport Oracle Net Copyright © 2006, Oracle. All rights reserved. 1 - 6 Types of Standby Databases There are two types of standby databases: • Physical standby database – Identical to the primary database on a block-for-block basis – Synchronized with the primary database through application of redo data received from the primary database • Logical standby database – Shares the same schema definition – Synchronized with the primary database by transforming the data in the redo received from the primary database into SQL statements and then executing the SQL statements Copyright © 2006, Oracle. All rights reserved. 1 - 7 Oracle Data Guard Broker Framework CLI management client Enterprise Manager Repository Primary database Data Guard broker Oracle Management Server Data Guard broker Agent Standby database Agent Copyright © 2006, Oracle. All rights reserved. 1 - 8 Types of Services There are three types of services provided with Data Guard: • Redo transport services • Log apply services – Redo Apply – SQL Apply • Role-management services Copyright © 2006, Oracle. All rights reserved. 1 - 9 Role Transitions: Switchover and Failover • Oracle Data Guard supports two role-transition operations: – Switchover — Planned role reversal — Used for OS or hardware maintenance – Failover — Unplanned role reversal — Use in emergency — Zero or minimal data loss depending on choice of data protection mode — Can be initiated automatically when fast-start failover is enabled • Role-transition operations are not automatically invoked. Copyright © 2006, Oracle. All rights reserved. 1 - 11 Data Protection Modes • Maximum protection • Maximum availability • Maximum performance [...]... upgrade using Data Guard SQL Apply Planned downtime 1 - 15 Copyright © 2006, Oracle All rights reserved Oracle Data Guard and Real Application Clusters Oracle Data Guard and Real Application Clusters are complementary and can be used together • Real Application Clusters provides high availability • Oracle Data Guard provides disaster protection and prevents data loss 1 - 16 Copyright © 2006, Oracle All... manager Oracle Application Server RAC production database 1 - 17 Data Guard Oracle Application Server RAC physical standby database Copyright © 2006, Oracle All rights reserved RAC logical standby database Summary In this lesson, you should have learned how to: • Describe the basic components of Oracle Data Guard • Describe the differences between physical and logical standby databases • Determine when Oracle. .. Copyright © 2006, Oracle All rights reserved Role of Data Guard in a High-Availability Architecture Computer failures RAC Storage failure ASM Human error Flashback technology Corruption Oracle HARD RMAN Site failure Data Guard Data failures 1 - 14 Copyright © 2006, Oracle All rights reserved Role of Data Guard in a High-Availability Architecture Data changes • Online schema and data reorganization... Oracle Data Guard is an appropriate solution in your Oracle Database configuration • Explain the use of Data Guard in high-availability architectures 1 - 18 Copyright © 2006, Oracle All rights reserved Practice 1: Overview This practice covers the following topics: • Reviewing the factors that affect planned and unplanned downtime • Reviewing the differences between physical and logical standby databases... Implementing Oracle Data Guard Oracle Data Guard provides the following benefits: • Continuous service through disasters or crippling data failures • Complete data protection against corruptions and data loss • Efficient use of system resources • Elimination of idle standby systems • Flexible configuration of your system to meet business protection and recovery requirements • Centralized management 1 - 13 Copyright... topics: • Reviewing the factors that affect planned and unplanned downtime • Reviewing the differences between physical and logical standby databases • Reviewing the components of Oracle Data Guard 1 - 19 Copyright © 2006, Oracle All rights reserved . © 2006, Oracle. All rights reserved. 1 - 5 What Is Oracle Data Guard? Primary database Standby database Database Database copy Redo transport Oracle Net. 1 Copyright © 2006, Oracle. All rights reserved. Oracle Data Guard: Overview Copyright © 2006, Oracle. All rights reserved. 1 - 2 Objectives