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 Guar
Trang 1Understanding the Oracle Data Guard Architecture
Trang 2After 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
Trang 3Data 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.
Trang 4Data 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.
Trang 5Oracle Data Guard: Architecture
ARC0
FAL
RFS
MRP or LSP
Archived redo
logs ARC0
Standby database
Reports
(MRP only)
Standby redo logs
Trang 6Primary Database Flow
ARC0
FAL
RFS
MRP or LSP
Archived redo
logs ARC0
Standby database
Reports
(MRP only)
Standby redo logs
Trang 7Standby Database Flow
ARC0
FAL
RFS
MRP or LSP
Archived redo
logs ARC0
Standby database
Trang 8Standby Redo Logs
Redo from
primary database
Standby redo logs
Archived redo logs
MRP/LSP
Standby database
Trang 9Physical Standby Database:
Redo Apply Architecture
Redo apply
Redo stream
Redo transport
Backup
Trang 10Logical Standby Database:
SQL
SQL Apply
Reports
Production database Logical standby database
Logical standby database
Trang 11Redo records
LCR LCR : Shared pool
Transaction groups
Transactions sorted in dependency order
Log Mining Apply processing
Logical change records not grouped into transactions
Transactions to
be applied
Analyzer Coordinator
Trang 12Real-Time Apply
RFS
Standby redo log files
Archived redo log files
Trang 13Setting the DB_UNIQUE_NAME Parameter
DB_UNIQUE_NAME = SF1_DB
San Francisco
SF1_DB
Trang 14Specifying Role-Based Destinations
Primary database database Standby
Trang 15Combinations for VALID_FOR
ONLINE_LOGFILE , PRIMARY_ROLE Valid Ignored Ignored ONLINE_LOGFILE , STANDBY_ROLE Ignored Ignored Valid ONLINE_LOGFILE , ALL_ROLES Valid Ignored Valid STANDBY_LOGFILE , STANDBY_ROLE Ignored Valid Valid
STANDBY_LOGFILE , ALL_ROLES Ignored Valid Valid ALL_LOGFILES , PRIMARY_ROLE Valid Ignored Ignored ALL_LOGFILES , STANDBY_ROLE Ignored Valid Valid ALL_LOGFILES , ALL_ROLES Valid Valid Valid
Trang 16Identifying Destination Settings
SQL> SELECT DEST_ID,VALID_TYPE,VALID_ROLE,VALID_NOW
2 FROM V$ARCHIVE_DEST;
DEST_ID VALID_TYPE VALID_ROLE VALID_NOW
- - -
1 ALL_LOGFILES ALL_ROLES YES
2 STANDBY_LOGFILE STANDBY_ROLE WRONG VALID_TYPE
3 ONLINE_LOGFILE STANDBY_ROLE WRONG VALID_ROLE
4 ALL_LOGFILES ALL_ROLES UNKNOWN
5 ALL_LOGFILES ALL_ROLES UNKNOWN
6 ALL_LOGFILES ALL_ROLES UNKNOWN
7 ALL_LOGFILES ALL_ROLES UNKNOWN
8 ALL_LOGFILES ALL_ROLES UNKNOWN
9 ALL_LOGFILES ALL_ROLES UNKNOWN
10 ALL_LOGFILES ALL_ROLES UNKNOWN
11 ALL_LOGFILES ALL_ROLES YES
11 rows selected.
Trang 17Standby Redo Log Configuration
Redo shipment
RFS
Standby redo logs
Online redo logs
Primary database
Standby database
Trang 18Using SQL to Add Standby Redo Logs
• Use the ALTER DATABASE statement to create the
standby redo log files:
• Add members to a group with the following statement:
• View information about the groups as follows:
SQL> ALTER DATABASE ADD STANDBY LOGFILE MEMBER
2 '/oracle/oradata/orcl/log2b.rdo' TO GROUP 2;
SQL> ALTER DATABASE ADD STANDBY LOGFILE
2 ('/oracle/oradata/orcl/log1c.rdo',
3 '/oracle/oradata/orcl/log2c.rdo') SIZE 500K;
SQL> SELECT * FROM v$standby_log;
SQL> SELECT * FROM v$logfile
2 WHERE type = 'STANDBY';
Trang 19Using Enterprise Manager
to Add Standby Redo Logs
Trang 20Standby Database Modes
You can maintain the standby data in one of the following modes:
• For physical standby databases
– Redo Apply
– Open read-only mode
• For logical standby databases
– Open read/write mode
Trang 21In this lesson, you should have learned how to describe the following:
• Data Guard architecture processes
• Operational requirements of a Data Guard environment
• How Data Guard processes, transports, and applies
redo logs
• Modes of standby databases and when to use each
mode
Trang 22Practice 2-1: Architecture Review
This practice covers the following topics:
• Reviewing the Oracle Data Guard architecture
• Reviewing the processes that Data Guard uses to
transport and apply redo logs
• Reviewing the modes that are used to recover a
primary database
Trang 23Practice 2-2: Installing the Oracle Management Agent
This practice covers the following topics:
• Installing the Oracle Management Agent
• Configuring monitoring credentials for your database
Trang 24Practice 2-3: Configuring Your Primary Database
This practice covers the following topics:
• Reviewing your primary database configuration
• Configuring your primary database in preparation for
creating a Data Guard configuration