When do I use Oracle Active Data Guard?

100$ Question,When do I use Oracle Active Data Guard?

Use Active Data Guard where emphasis is on simplicity, best data protection, data availability and highest performance:

• Secure physical replication, standby database is open read-only, it is impossible to modify standby data independent of primary transactions
• Simplest, fastest, one-way replication of a complete Oracle Database. No requirements for supplemental logging or performance implications for tables having no primary key or unique index. Little if any performance tuning required at the standby database, the default configuration handles most workloads.
• No restrictions - Oracle Data Guard Redo Apply supports all Oracle features and transparently replicates all data and storage types, PL/SQL packages and DDL without special considerations
• Best data protection – Replication direct from memory isolates the standby from I/O corruption that can occur at the primary database. Detect silent lost-write corruption that can occur independently on primary or standby. Automatically detect and repair physical block corruption that can occur independently on primary or standby.
• Choice of synchronous with zero data loss, or asynchronous with near-zero data loss protection
• Simple to improve ROI by offloading read-only workload and/or backups to a synchronized physical standby
• Transparency of backups - an Oracle Data Guard primary and standby are physically exact copies of each other, RMAN backups are completely interchangeable
• Minimize planned downtime and risk using Data Guard standby; standby first patching, database rolling upgrades, and select platform migrations (see My Oracle Support Note 413484.1 for mixed platform combinations)
• A single command will convert a physical standby database as a test system open read-write. A second command will convert it back to a physical standby database and resynchronize it with the primary; primary data is protected at all times.
• Integrated management of a complete configuration - Oracle Data Guard Broker command line or Oracle Enterprise Manager Cloud Control, integrated automatic database and client failover

Active Data Guard is a superset of Data Guard capabilities included with Oracle Enterprise Edition and can be purchased as the Active Data Guard Option for Oracle Database Enterprise Edition. It is also included with every Oracle GoldenGate license, offering customers the ability to acquire the complete set of advanced Oracle replication capabilities with a single purchase. Basic Data Guard functionality does not require a separate license, it is included with Oracle Enterprise Edition.

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Data Guard Benefits

Data Guard Benefits

Data Guard offers these benefits:

• Disaster recovery, data protection, and high availability
  Data Guard provides an efficient and comprehensive disaster recovery and high availability solution. Easy-to-manage switchover and failover capabilities allow role reversals between primary and standby databases, minimizing the downtime of the primary database for planned and unplanned outages.
  
• Complete data protection
  Data Guard can ensure zero data loss, even in the face of unforeseen disasters. A standby database provides a safeguard against data corruption and user errors. Because the redo data received from a primary database is validated at a standby database, storage level physical corruptions on the primary database do not propagate to the standby database. Similarly, logical corruptions or user errors that cause the primary database to be permanently damaged can be resolved.
  
• Efficient use of system resources
  The standby database tables that are updated with redo data received from the primary database can be used for other tasks such as backups, reporting, summations, and queries, thereby reducing the primary database workload necessary to perform these tasks, saving valuable CPU and I/O cycles.
  
• Flexibility in data protection to balance availability against performance requirements
  Oracle Data Guard offers maximum protection, maximum availability, and maximum performance modes to help enterprises balance data availability against system performance requirements.
  
• Automatic gap detection and resolution
  If connectivity is lost between the primary and one or more standby databases (for example, due to network problems), redo data being generated on the primary database cannot be sent to those standby databases. Once a connection is reestablished, the missing archived redo log files (referred to as a gap) are automatically detected by Data Guard, which then automatically transmits the missing archived redo log files to the standby databases. The standby databases are synchronized with the primary database, without manual intervention by the DBA.
  
• Centralized and simple management
  The Data Guard broker provides a graphical user interface and a command-line interface to automate management and operational tasks across multiple databases in a Data Guard configuration. The broker also monitors all of the systems within a single Data Guard configuration.
  
• Integration with Oracle Database
  Data Guard is a feature of Oracle Database Enterprise Edition and does not require separate installation.
  
• Automatic role transitions
  When fast-start failover is enabled, the Data Guard broker automatically fails over to a synchronized standby site in the event of a disaster at the primary site, requiring no intervention by the DBA. In addition, applications are automatically notified of the role transition.