2 Understanding the Oracle Data Guard Architecture

2
Copyright © 2006, Oracle. All rights reserved.
Understanding the Oracle
Data Guard Architecture
Copyright © 2006, Oracle. All rights reserved.
2 - 2
Objectives
After completing this lesson, you should be able to do the
following:
•
Describe the Data Guard architecture
•
Explain the operational requirements of Data Guard
•
Describe how Data Guard processes, transports, and
applies redo logs
•
Describe standby database modes
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2 - 3
Data Guard Operational Requirements: Hardware
and Operating System
•
The hardware can be different for the primary and
standby databases.
•
The operating system and platform architecture for the
primary and standby databases must be the same.
•
The operating system releases for the primary and
standby databases can be different.

•
If all databases are on the same system, verify that the
OS allows you to mount more than one database with
the same name.
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2 - 4
Data Guard Operational Requirements: Oracle
Database Software
•
Same release of Oracle Database Enterprise Edition
must be installed for all databases.
•
SYSDBA privileges are required for the accounts used to
manage the database instances.
•
Each database must have its own control file.
•
Primary database must operate in ARCHIVELOG mode.
•
Enable FORCE LOGGING on the primary database before
taking data file backups for standby creation.
•
If any databases use ASM and/or OMF, all should use
the same combination.
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2 - 6
Oracle Data Guard: Architecture
LGWR
Primary
database

transactions
Online
redo
logs
ARC0
FAL
RFS
MRP or
LSP
Archived redo
logs
ARC0
Standby
database
Reports
(MRP only)
Standby
redo logs
Archived redo
logs
Backup
Oracle net
LNSn
(Real-time
apply)
Copyright © 2006, Oracle. All rights reserved.
2 - 7
Primary Database Flow
LGWR
Primary

database
transactions
Online
redo
logs
ARC0
FAL
RFS
MRP or
LSP
Archived redo
logs
ARC0
Standby
database
Reports
(MRP only)
Standby
redo logs
Archived redo
logs
Backup
Oracle net
LNSn
(Real-time
apply)
Copyright © 2006, Oracle. All rights reserved.
2 - 8
Standby Database Flow
LGWR

Primary
database
transactions
Online
redo
logs
ARC0
FAL
RFS
MRP or
LSP
Archived redo
logs
ARC0
Standby
database
Oracle net
Reports
(MRP only)
Standby
redo logs
Archived redo
logs
Backup
LNSn
(Real-time
apply)
Copyright © 2006, Oracle. All rights reserved.
2 - 9
Standby Redo Logs

Redo from
primary database
RFS
ARC0
Standby
redo logs
Archived
redo logs
MRP/LSP
Standby database
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2 - 10
Physical Standby Database:
Redo Apply Architecture
Physical standby
database
Primary
database
Production
database
Physical standby
database
Redo
apply
Redo
stream
Redo
transport
Backup