Oracle Data Guard AFR v1.1
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Transcript of Oracle Data Guard AFR v1.1
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Oracle Data Guard ngel Freire R.Oracle Consultant
11-09-2014
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High Availability
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High Availability Features
1. Confidence
2. Recoverability
3. Detecting errors in real time
4. Continuity of Operations
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Analysis of High Availability
1. Business Impact Analysis
2. The cost of Downtime
3. Recovery Time Objective (RTO)
4. Recovery Point Objective (RPO)
5. Total Cost of Ownership (TCO)
6. Return on Investment (ROI)
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High Availability Systems
1. Layer 1 (Billing, Sales)
2. Layer 2 (Purchasing, Inventory)
3. Layer 3 (BI)
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Cost and High Availability
1. Maximum tolerated stop.
2. Maximum frequency of stops tolerated.
3. Easily quantifiable costs (sales, inactive employees, contractual
penalties)
4. Difficult to quantify costs (Legal Proceedings)
5. Unquantifiable costs (negative publicity, angry customers)
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Implementing High Availability
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Oracle High Availability Solutions
Fast-Start Fault Recovery
Oracle Restart
Oracle Real Application Clusters and Oracle Clusterware Oracle RAC
One Node
Oracle Data Guard
Oracle GoldenGate and Oracle Streams Oracle
Flashback Technology
Oracle Automatic Storage Management Fast
Recovery Area
Recovery Manager Data
Recovery Advisor Oracle
Secure Backup Oracle
Security Features LogMiner
Oracle Exadata Storage Server Software (Exadata Cell) Oracle
Exadata Database Machine
Oracle Database File System (DBFS) Client
Failover
Automatic Block Repair
Corruption Prevention, Detection, and Repair
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Planned outages
Operating system and hardware upgrades -> Oracle
RAC Oracle Database patches -> Oracle RAC
Oracle Grid Infrastructure upgrades and patches -> Oracle RAC
Storage Migration -> Oracle ASM
Migrating to Exadata Storage -> Oracle MAA best practices
Upgrading Exadata Storage -> Exadata Patch Manager
Migrating a single-instance database to Oracle RAC -> Oracle Grid Infrastructure
Migrating to Oracle ASM -> Oracle Data Guard
Migrating a single-instance database to Oracle RAC -> Oracle Data Guard
Patch set and database upgrades -> Oracle Data Guard using SQL Apply
Oracle interim patches, Oracle clusterware upgrades and patches, Oracle ASM upgrades
Operating System and Hardware Upgrades -> Oracle Data Guard Standby-First Patch Apply
Migration across Windows and Linux -> Oracle Data Guard
Platform migration across the same endian format platforms -> Transportable database
Platform migration across different endian format platforms -> Transportable tablespace
Patch set and database upgrades, platform migration, rolling upgrades, and when different
character sets are required -> Oracle GoldenGate and Oracle Streams
Application upgrades -> Online Application Maintenance and Upgrades
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No Planned outages
Site Failures -> Oracle Data Guard
Site Failures -> Oracle GoldenGate and Oracle
Streams Site Failures -> Recovery Manager
Computer Failures -> Oracle Real Application Clusters and Oracle Clusterware
Computer Failures -> Oracle RAC One Node
Computer Failures -> Fast-Start Fault Recovery
Computer Failures -> Oracle Data Guard
Computer Failures -> Oracle GoldenGate and Oracle
Streams Storage Failures -> Oracle Automatic Storage
Management Storage Failures -> Oracle Data Guard
Storage Failures -> RMAN with Fast Recovery Area and Oracle Secure Backup
Storage Failures -> Oracle GoldenGate and Oracle Streams
Data Corruption -> Oracle Exadata Storage Server Software (Exadata Cell) and Oracle ASM Data
Corruption -> Corruption Prevention, Detection, and Repair
Data Corruption -> Data Recovery Advisor and RMAN with Fast Recovery Area
Data Corruption -> Oracle Data Guard
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No Planned outages
Data Corruption -> Oracle GoldenGate and Oracle Streams
Human Errors -> Oracle Security
Features Human Errors -> Oracle
Flashback Technology Human Errors ->
LogMiner
Lost writes -> Oracle Data Guard, RMAN, DB_LOST_WRITE_PROTECT
Lost writes -> Oracle Data Guard Oracle Exadata Storage Server Software (Exadata Cell)
Hangs or slow down - Oracle Database and Oracle Enterprise Manager
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Oracle Data Guard: Evolucin
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New Features Data Guard 10.1
Data Guard Broker Support for RAC Automatic
LogMiner Configuration
Log Miner Support for Index-Organized Tables
LogMiner Support for More Types: LONG, Multibyte CLOB and NCLOB
Fine-Grained Supplemental Logging
Secured Redo Transmission
Uniquely Named Databases with DB_UNIQUE_NAME
Simplified Zero Data Loss for Data Guard SQL Apply
Zero Downtime Instantiation for SQL Apply
Real Time Apply
Automating Recovery Through Open Resetlogs in Standby Databases
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New Features Data Guard 10.2
Fast-Start Failover
Automatic Conversion of the Primary Database to a Standby Database Upon Failover
Optimized Asynchronous Redo Transmission
Faster Redo Apply Failover
Faster SQL Apply Failover
Additional Data Type Support in LogMiner and SQL Apply
Automatic Deletion of Applied Archive Logs
Data Guard: Improved Manageability for Redo Transport, Log Apply, and Broker
Easy Conversion of a Physical Standby Database to a Reporting Database
Flashback Across Data Guard Switchovers
Fine-Grained, Automated Tracking of SQL Apply Runtime Performance
Optimized Creation of Logical Standby Database
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New Features Data Guard 11.1
Fast-Start Failover for Maximum Performance Mode
Compression of Redo Traffic (Only for Gap Resolution)
Real-Time Query Capability of Physical Standby Database
Fast Role Transitions in a Data Guard Configuration
User Configurable Conditions to Initiate Fast-Start Failover
Dynamic Setting of Oracle Data Guard SQL Apply Parameters
Enhanced Data Guard Broker Based Management Framework
Enhanced Data Guard Management Interface (Using SQL*Plus)
Histogram for Redo Transport Response TimeSnapshot Standby
Strong Authentication for Data Guard Redo Transport
Enhanced DDL Handling in Oracle Data Guard SQL Apply
Enhanced Oracle RAC Switchover Support for Logical Standby Databases
Oracle Scheduler Support in Data Guard SQL Apply
Fine-Grained Auditing (FGA) Support in Data Guard SQL Apply Support
Transparent Data Encryption (TDE) with Data Guard SQL Apply
Support XMLType Data Type (Only CLOB) in Data Guard SQL Apply
Virtual Private Database (VPD) Support in Data Guard SQL Apply
SMP Scalable Redo Apply
Archive Log Management Improvements
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New Features Data Guard 11.2
Automatic Block Repair
Compressed Table Support in Logical Standby Databases and Oracle LogMiner
Configurable Real-Time Query Apply Lag Limit
Integrated Support for Application Failover in a Data Guard Configuration
Support Up to 30 Standby Databases
Universal Connection Pool (UCP) Integration with Oracle Data Guard
Enable Sampling for Active Data Guard
SQL Apply Support for Object Relational Model
SQL Apply Support for Binary XML
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Oracle Data Guard Concepts
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Configurations
Primary database Physicalstandby database Logical
standby databaseSnapshot Standby Database
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Services
Redo Transport ServicesApply Services
Role Transitions
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Role Transitions
SwitchoverSwitchback
FailoverReinstateConvert
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Interfaces
Enterprise Manager / Grid ControlDGMGRL
SQL*PlusInitialization Parameters
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Complementary Technologies
Oracle RACFlashback Database
RMAN
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Why Data Guard?
AdvantageDisaster protection.
Complete protection of data.Efficient use of resources.
Flexibility between availability and performance.
Flexibility between configurations.
Automatic detection and resolution erros.
Simple and centralized management.
Full integration with Oracle Database.
Automatic role transitions.
DisadvantageIncreased complexity of the environment.Higher cost of Licensing.Higher cost of Hardware.Higher cost of knowledge.
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Physical Standby
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Why Physical Standby?
Advantage
Protection against disasters.Data protection.Load Reduction of production (RMAN, SQL Read Only).Low impact on production.
Disadvantages
Database available only for reading.Standby must be an exact copy of Production
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Parameters
COMPATIBLE (Todos)
CONTROL_FILE_RECORD_KEEP_TIME (Todos)
CONTROL_FILES (Todos)
DB_FILE_NAME_CONVERT (Physical Standby, Snapshot Standby)
DB_UNIQUE_NAME (Todos)
FAL_CLIENT (Physical Standby, Snapshot Standby) Obsolete
FAL_SERVER (Physical Standby, Snapshot Standby)
INSTANCE_NAME (Todos)
LOG_ARCHIVE_CONFIG(Todos)
LOG_ARCHIVE_DEST_n (Todos)
LOG_ARCHIVE_DEST_STATE_n (Todos) ENABLE, DEFER or ALTERNATE.
LOG_ARCHIVE_FORMAT (Todos)
LOG_ARCHIVE_LOCAL_FIRST (Primary, Snapshot Standby) Obsolete
LOG_ARCHIVE_MAX_PROCESSES (Todos)
LOG_ARCHIVE_MIN_SUCCEED_DEST (Todos)
LOG_ARCHIVE_TRACE (Todos)
LOG_FILE_NAME_CONVERT (Physical Standby, Logical tandby, Snapshot Standby)
REMOTE_LOGIN_PASSWORDFILE(Todos)
SHARED_POOL_SIZE (Todos)
STANDBY_ARCHIVE_DEST (Physical Standby, Logical Standby, Snapshot Standby) Obsolete
STANDBY_FILE_MANAGEMENT (Primary, Physical Standby, Snapshot Standby)
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LOG_ARCHIVE_DEST_n
AFFIRM / NOAFFIRMALTERNATE
COMPRESSIONDB_UNIQUE_NAMEDELAYLOCATION and SERVICEMANDATORYMAX_CONNECTIONS
MAX_FAILURENET_TIMEOUTNOREGISTERREOPENSYNC / ASYNCTEMPLATE
VALID_FOR
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Protection Mode
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Protection Mode
Maximum Performance (NOAFFIRM, ASYNC) Maximum Availability (AFFIRM, SYNC) Maximum Protection (AFFIRM, SYNC)
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Maximum Performance
Maximum performance mode is the default level of data protection.
This mode provides the highest possible level of data protection without affecting the
performance of the primary database. Transactions can commit as soon as the redo data is written to the local online redo log.
Redo data is shipped to the standby database asynchronously with respect to the
commitment of the transactions that create the redo data.
Configuration requirements:
Standby redo log on at least one standby database
At least one standby database that is configured with the ASYNC and NOAFFIRM redo
transport attributes
Maximum Performance Mode Maximum performance is the default protection mode and provides thehighest possible level of data protection without affecting the performance of the primary database.This is accomplished by allowing a transaction to commit as soon as the redo data needed to recoverthat transaction is written to the local online redo log. The primary databases redo data is also written
to at least one standby database, but that redo data is written asynchronously with respect to the
commitment of the transactions that create the redo data. When network links with sufficient bandwidthare used, this mode provides a level of data protection that approaches that of maximum availabilitymode with minimal impact on primary database performance. Maximum performance moderequirement: Set the ASYNC and NOAFFIRM redo transport attributes of the LOG_ARCHIVE_DEST_n parameter on at least one standby database.
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Maximum Availability
Maximum availability mode ensures zero data loss withoutcompromising the availability of the primary database. Redo data must be written to both the local online redo log and
the standby redo log on at least one synchronized standbydatabase. The primary database does not shut down if it cannot write to
at least one synchronized standby database. If no synchronized standby databases are available, theprimary database operates in an unsynchronized mode until atleast one standby database is synchronized. Configuration requirements: At least one standby database
must have a standby redo log, and that standby database
destination must be configured with the SYNC and AFFIRMredo transport attributes.
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Maximum Availability
Maximum Availability Mode This protection mode provides the highest possible level of data
protection without compromising the availability of the primary database. A transaction does notcommit until the redo that is needed to recover that transaction is written to the local online redolog and to at least one remote standby redo log. The primary database does not shut down if afault prevents it from writing its redo stream to a remote standby redo log. Instead, the primarydatabase operates in an unsynchronized mode until the fault is corrected and all gaps in redo logfiles are resolved. When all gaps are resolved and the standby database is synchronized, theprimary database automatically resumes operating in maximum availability mode. This modeguarantees that no data loss occurs if the primary database failsbut only if a second fault doesnot prevent a complete set of redo data from being sent from the primary database to at least
one standby database. Maximum availability mode requirements: Configure standby redo log files on at least one standby database.
Set the SYNC and AFFIRM attributes of the LOG_ARCHIVE_DEST_n parameter for at leastone standby database.
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Maximum Protection
Maximum protection mode ensures zero data loss in the event of a
failure of the primary database, the network, or all standby databases. The primary database shuts down if a fault prevents it from writing its
redo stream to at least one synchronized standby database.
Redo data must be written to both the local online redo log and the
standby redo log on at least one synchronized standby database.
Configuration requirements: At least one standby database must have
a standby redo log, and that standby database destination must be
configured with the SYNC and AFFIRM redo transport attributes.
Maximum Protection Mode This protection mode ensures that no data loss occurs if the primary databasefails. To provide this level of protection, the redo data that is needed to recover each transaction must bewritten to both the local online redo log and the standby redo log on at least one standby database before thetransaction commits. To ensure that data loss cannot occur, the primary database shuts down if a fault preventsit from writing its redo stream to at least one remote standby redo log. For multiple-instance RAC databases,Data Guard shuts down the primary database if it is unable to write the redo records to at least one properlyconfigured database instance. Maximum protection mode requirements: Configure standby redo log files on at least one standby database.
Set the SYNC and AFFIRM attributes of the LOG_ARCHIVE_DEST_n parameter for at least one standbydatabase destination.Note: Oracle recommends a minimum of two standby databases for maximum protection mode.
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Role Transitions
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Role Transitions: Switchover and Failover
Switchover
Planned role transition Used for operating-system or hardware maintenance
Manually invoked on primary database
Failover
Unplanned role transition
Used in an emergency
Minimal or no data loss (depending on the data-protection mode)
Fast-start failover can be enabled for automatic failover
Initiated at standby database
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Switchover
Transitions the roles of the primary and standby databases
Requires no resetting of the online redo logs of the new primary database Incurs no data loss
A switchover operation transitions the primary database to the standby role and transitions the standbydatabase to the primary role, without resetting the online redo logs of the new primary database. The primarydatabase at the start of a switchover operation will need to be shutdown and restarted. The physical standbydatabase is not shutdown and restarted during a switchover. If the physical standby database is in the Active
Data Guard mode, it is closed for the transition then opened again after the switchover completes, but it isnever totally shutdown to require a restart. If the switchover operation involves a logical standby database,there is no need to shut down and restart either the primary database or any of the standby databases. Logicalstandby databases do not need to be shut down and restarted.Note: When necessary, the broker automatically starts and stops all but one instance in a Real ApplicationClusters (RAC) environment for the primary database. If the broker is not used, this must be done manually.Starting with Oracle Database 11g Release 2 (11.2), the secondary RAC instances of a physical standbydatabase no longer need to be shutdown during the switchover. They can stay in the mounted or Active DataGuard state. The primary still requires only one instance be running during a switchover.
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Switchover
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Switchover
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Failover
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Types of Failovers
Manual failover: Invoked by the DBA
Complete: Attempts to minimize data loss by applying all available redoon the standby database
Immediate: No additional data is applied on the Standby database
Fast-start failover: Invoked automatically by the Data Guard broker
Types of FailoversA manual failover is invoked through DGMGRL or Enterprise Manager. There are two
types of manual failover: Complete: The maximum amount of redo data for the protection mode is recovered. In this type of failover,the broker avoids disabling any standby databases that are not the failover target. Complete failover is thedefault and recommended type of failover. Immediate: No additional redo data is applied to the standby database after the failover is invoked. This isthe fastest type of failover. After an immediate failover, you must recreate or reinstate the original primarydatabase and all standby databases that were not a target of the failover.Note: You should always try to perform a complete failover. Perform an immediate failover only when acomplete failover is unsuccessful. Depending on the destination attributes of redo transport services, acomplete failover can take place without incurring any data loss, while an immediate failover usually results inthe loss of data. You can configure fast-start failover so that the broker automatically fails over to a chosenstandby database in the event of the loss of the primary database. For details, see the lesson titled Enabling
Fast-Start Failover.
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Failover Considerations
The old primary database is disabled from the Data Guard configuration.
Data loss is possible. Failover should be used only in an emergency.
When choosing a standby database to fail over to, you should:
Choose a physical standby database when possible
Choose the standby database that is most current
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Logical Standby
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Logical Standby
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Por que Logical Standby?
Additional types of protection against failures.Efficient use of resources.
Load distribution.
Optimization for reporting and decision support requirements.
Minimize downtime during upgrades.
Advantage
Disadvantages
Several limitations of data types.Several SQL commands limitations.SQL command application, not the REDO LOG.
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Data types not supported
BFILE
Collections (VARRAYS, Nested Tables) MultimediaData types (Spatial, Image, Oracle Text) ROWID, UROWID
User-defined types XMLType
(Object Relational) Binary
XML
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SQL commands ignored
ALTER DATABASE
ALTER MATERIALIZED VIEW ALTER
MATERIALIZED VIEW LOGALTER SESSION
ALTER SYSTEM
CREATE CONTROL FILE
CREATE DATABASE
CREATE DATABASE LINK
CREATE PFILE FROM SPFILE
CREATE MATERIALIZED VIEW
CREATE MATERIALIZED VIEW LOG
CREATE SCHEMA AUTHORIZATION
CREATE SPFILE FROM PFILE DROP
DATABASE LINK
DROP MATERIALIZED VIEWDROP MATERIALIZED VIEW LOG
EXPLAIN
LOCK TABLE
SET CONSTRAINTS
SET ROLE
SET TRANSACTION
l d
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Oracle Dataguard Views
DBA_LOGSTDBY_EVENTSDBA_LOGSTDBY_HISTORYDBA_LOGSTDBY_LOGDBA_LOGSTDBY_NOT_UNIQUEDBA_LOGSTDBY_PARAMETERSDBA_LOGSTDBY_SKIPDBA_LOGSTDBY_SKIP_TRANSACTION
DBA_LOGSTDBY_UNSUPPORTEDV$LOGSTDBY_PROCESSV$LOGSTDBY_PROGRESSV$LOGSTDBY_STATEV$LOGSTDBY_STATSV$LOGSTDBY_TRANSACTION
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Active Data Guard
O l A i D G d
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Oracle Active Data Guard
Is an option for Oracle Database 11 g Enterprise Edition
Enhances quality of service by offloading resource intensive activities froma production database to a
standby database
Includes the following features:
Real-time query
RMAN block change tracking on a physical Standby database
Oracle Active Data Guard is a separately licensed database option for Oracle Database 11gEnterprise Edition. It includes the Real-time Query feature, which enables a physicalstandby database to be open read-only while Redo Apply is active. With this feature, userswho are connected to a physical standby database can query and report against data that
is up-todate with the primary database. Oracle Active Data Guard also enables you toconfigure RMAN block change tracking for a physical standby database. With RMAN blockchange tracking, you can offload fast incremental backups from the production database tothe physical standby database.
U i R l Ti Q
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Using Real-Time Query
U i R l Ti Q
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Using Real-Time Query
With Oracle Active Data Guard, you can use a physical standby databasefor queries while redo is applied to the physical standby database. Thisfeature enables you to use a physical standby database for disasterrecovery and to offload work from the primary database during normaloperation.Note: If you need to create additional structures (such as indexes andmaterialized views), you can create a logical standby database as
described in the lesson titled Creating a Logical Standby Database. Inaddition, this feature provides a loosely coupled read/write clusteringmechanism for OLTP workloads when configured as follows: Primary database: Recipient of all update traffic Several readable standby databases: Used to distribute the queryworkload The physical standby database can be opened in read-only
mode only if all files were recovered up to the same system changenumber (SCN). Otherwise, the open fails.
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Snapshot Standby
Snapshot Standb
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Snapshot Standby
A snapshot standby database is a fully updatable Standby database
created by converting a physical Standby database. Snapshot standby databases receive and archivebut do not applyredo
data from a primary database.
When the physical standby database is converted, an implicit guaranteed
restore point is created and Flashback Database is enabled.
A snapshot standby database is a fully updatable standby database that is created byconverting a physical standby database to a snapshot standby database. A snapshot standbydatabase receives and archivesbut does not applyredo data from a primary database.Redo data received from the primary database is applied when a snapshot standby databaseis converted back to a physical standby database, after discarding all local updates to thesnapshot standby database. You can create a snapshot standby database by using DGMGRLcommands or SQL commands. When the standby database is converted to a snapshot
standby database, an implicit guaranteed restore point is created and Flashback Database isenabled. After performing operations on the snapshot standby database, you can convert itback to a physical standby database. Data Guard implicitly flashes the database back to theguaranteed restore point and automatically applies the primary database redo that wasarchived by the snapshot standby database since it was created. The guaranteed restore pointis dropped after this process is completed.
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Data Guard Broker
Data G ard Broker
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Data Guard Broker
Data Guard Broker
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Data Guard Broker
Data Guard Broker Components
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Data Guard Broker Components
Client-side: Oracle Enterprise Manager Grid Control DGMGRL (command-line interface) Server-side: Data Guard monitor DMON process Configuration files
Data Guard Broker Components
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Data Guard Broker Components
Data Guard Broker: Components The Oracle Data Guard broker consists of both client-sideand server-side components. On the client, you can use the following Data Guard
components to define and manage a configuration: Oracle Enterprise Manager
DGMGRL, which is the Data Guard command-line interface (CLI) On the server, the DataGuard monitor is a broker component that is integrated with the Oracle database. The DataGuard monitor comprises the Data Guard monitor (DMON) process and broker configurationfiles, with which you can control the databases of that configuration, modify their behavior atrun time, monitor the overall health of the configuration, and provide notification of other
operational characteristics. The configuration file contains profiles that describe the currentstate and properties of each database in the configuration. Associated with each databaseare various properties that theDMON process uses to control the databases behavior. The properties are recorded in the
configuration file as a part of the databases object profile that is stored there. Many
database properties are used to control database initialization parameters related to the DataGuard environment.
Oracle Data Guard Broker: Features
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Oracle Data Guard Broker: Features
The Oracle Data Guard broker is a distributed management framework.
The broker automates and centralizes the creation, maintenance, and
monitoring of Data Guard configurations. With the broker, you can perform all management operations locally or
remotely with easy-to-use interfaces: Oracle Enterprise Manager Grid Control DGMGRL (a command-line interface)
The following are some of the operations that the broker automates and simplifies: Automated creation of Data Guard configurations incorporating a primary database, a new or existing
standby database, redo transport services, and log apply servicesNote:Any of the databases in the configuration can be a Real Application Clusters (RAC) database. Adding new or existing standby databases to each existing Data Guard configuration, for a total of one
primary database and from one to 30 standby databases in the same configuration Managing an entire Data Guard configuration (including all databases, redo transport services, and log apply
services) through a client connection to any database in the configuration
Invoking switchover or failover with a single command to initiate and control complex role changes across alldatabases in the configuration Monitoring the status of the entire configuration, capturing diagnostic information, reporting statistics (such as
the log apply rate and the redo generation rate), and detecting problems quickly with centralized monitoring,testing, and performance tools
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