Oracle Support Master Note For Oracle Flashback Technologies (Doc ID 1138253.1)

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Master Note For Oracle Flashback Technologies (Doc ID 1138253.1)
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In this Document
  Purpose
  Scope and Application
  Master Note For Oracle Flashback Technologies
     Flash Recovery Area
     Flashback Database
     Flashback Drop
     Flashback Table
     Flashback Query
     Flashback Versions
     Flashback Transaction
     Flashback Data Archive
     Flashback & Dataguard
     Related Master Notes
     Using My Oracle Support Effectively
     Generic Links


Applies to: Oracle Server - Enterprise Edition - Version: 10.1.0.2 to 11.2.0.2 - Release: 10.1 to 11.2 Information in this document applies to any platform.


Purpose

This Master Note is intended to provide an index and references to the most frequently used My Oracle Support Notes with respect to Flashback Technology. This Master Note is subdivided into categories to allow for easy access and reference to notes that are applicable to your area of interest, within the Flashback Technology.This includes the following categories:

  • Getting Started with Flashback Technologies
  • Flash Recovery Area
  • Flashback Database
  • Flashback Drop
  • Flashback Table
  • Flashback Query
  • Flashback Version
  • Flashback Transaction
  • Flashback Data Archive
  • Flashback and Dataguard
  • Related Master Notes
  • Using My Oracle Support Effectively
  • Generic Links

Scope and Application

Oracle9i introduced Flashback Query to provide a simple, powerful and completely non-disruptive mechanism for recovering from human errors. It allows users to view the state of data at a point in time in the past without requiring any structural changes to the database.

Oracle Database 10g extended the Flashback Technology to provide fast and easy recovery at the database, table, row, and transaction level. Flashback Technology revolutionizes recovery by operating just on the changed data. The time it takes to recover the error is now equal to the same amount of time it took to make the mistake. Oracle 10g Flashback Technologies includes Flashback Database, Flashback Table, Flashback Drop, Flashback Versions Query, and Flashback Transaction Query.

Flashback technology can just as easily be utilized for non-repair purposes, such as historical auditing with Flashback Query and undoing test changes with Flashback Database. Oracle Database 11g introduces an innovative method to manage and query long-term historical data with Flashback Data Archive. This release also provides an easy, one-step transaction backout operation, with the new Flashback Transaction capability.

This note applies to the following versions of these products:

Oracle Server - Enterprise Edition - Version: 10.2.0.1 to 10.2.0.x
Oracle Server - Enterprise Edition - Version: 11.1.0.6 to 11.1.0.x
Oracle Server - Enterprise Edition - Version: 11.2.0.1 to 11.2.0.x

Master Note For Oracle Flashback Technologies

Getting Started with Flashback Technologies

If a major error occurs, such as a batch job being run twice in succession, the database administrator can request a Flashback operation that quickly recovers the entire database to a previous point in time, eliminating the need to restore backups and do a point-in-time recovery. In addition to Flashback operations at the database level, it is also possible to flash back an entire table. Similarly, the database can recover tables that have been inadvertently dropped by a user.

++ Oracle Flashback Database lets you quickly bring your database to a prior point in time by undoing all the changes that have taken place since that time. This operation is fast, because you do not need to restore the backups. This in turn results in much less downtime following data corruption or human error.

++ Oracle Flashback Table lets you quickly recover a table to a point in time in the past without restoring a backup.

++ Oracle Flashback Drop provides a way to restore accidentally dropped tables.

++ Oracle Flashback Query lets you view data at a point-in-time in the past. This can be used to view and reconstruct lost data that was deleted or changed by accident. Developers can use this feature to build self-service error correction into their applications, empowering end-users to undo and correct their errors.

++ Oracle Flashback Version Query uses undo data stored in the database to view the changes to one or more rows along with all the metadata of the changes.

++ Oracle Flashback Transaction Query lets you examine changes to the database at the transaction level. As a result, you can diagnose problems, perform analysis, and audit transactions.

Below is a table which provides a pictorial explanation of all the flashback features.

   


Here are a few articles which help you in understanding the flashback technologies in a better way.


Note.435998.1 What Do All 10g Flashback Features Rely on and what are their Limitations ?
Note.203515.1 HA Frequently Asked Questions

Flash Recovery Area

The flash recovery area is an Oracle-managed directory, file system, or Automatic Storage Management disk group that provides a centralized disk location for backup and recovery files. All the files you need to completely recover a database from a media failure are part of the Flash Recovery Area. Oracle creates archived logs and flashback logs in the flash recovery area. Flashback logs are the key to flashback the database just like the archives being key to recover the database.

The articles mentioned in the following section help you in understanding the concepts and working of flash recovery area and troubleshooting flash recovery area issues.

Note.305648.1 What is a Flash Recovery Area and how to configure it ?
Note.369759.1 FLASH RECOVERY AREA and FLASHBACK database
Note.833663.1 Flash Recovery Area - FAQ
Note.560133.1 Benefits Of Using Flash Recovery Area
Note.315098.1 How is the space pressure managed in the Flash Recovery Area - An Example.
Note.305812.1 Flash Recovery area - Space management Warning & Alerts
Note.829755.1 Space issue in Flash Recovery Area( FRA )
Note.305810.1 Configuring file creation in Flash recovery area and order of Precedence
Note.305651.1 How to change Flash Recovery Area to a new location ?
Note.762934.1 Flash Recovery Area Sizing

Flashback Database

FLASHBACK DATABASE provides the ability to quickly revert an Oracle database to a previous time--without restoring datafiles and performing media recovery. When you enable the flashback functionality, Oracle automatically creates, deletes, and manages flashback database logs inside the flash recovery area. When you run the FLASHBACK DATABASE command, Oracle applies the flashback logs as well as the archived redo logs to return the database to the specified time. Its a rewind button for the Oracle database.

The articles listed below help you in understanding the concepts,configuration,usage and known issues of the flashback database feature:

Note.249319.1 Configure flashback database
Note.565535.1 Flashback Database Best Practices & Performance
Note.834824.1 Recovering Dropped User using Flashback Database
Note.330535.1 Restore Points in Oracle10g Release2
Note.369759.1 FLASH RECOVERY AREA and FLASHBACK database
Note.761126.1 CALCULATE THE VOLUME OF FLASHBACK LOG GENERATION
Note.369755.1 Flashback Logs-Space management
Note.427222.1 FLASHBACK LOGS NOT PURGED WHEN ARCHIVER DOESN'T HAVE DISK SPACE
Note.454768.1 Can you use flashback database if a period of noarchivelog exists
Note.566647.1 Guaranteed Restore Point with Flashback Database disabled generates too many flashback logs
Note.833584.1 How To Disable Flashback Database Without A Bounce
Note.828410.1 High "Flashback buf free by RVWR" waits
Note.386262.1 Cloning database using EM Fails If flashback is ON
Note.342764.1 Flashback 'ON' fails with ORA-38706 and ORA-38714
Note.829254.1 Database Crashed With ORA-19815 ORA-19809 ORA-16038
Note.847090.1 Flashback Database Failed With ORA-19554 and ORA-27001
Note.554445.1 ORA-26040 FLASHBACK DATABASE WITH NOLOGGING OBJECTS/ACTIVITIES RESULTS IN CORRUPTION
Note.444389.1 Querying V$Flashback_Database_Log Or Flashing Back Database to Before Resetlogs Triggers ORA-07445 [krfbDoConvertPlugin]
Note.982104.1 Workaround for Flashback Database fails with ORA-38753 ORA-01110

Flashback Drop

Flashback Drop provides a safety net when dropping objects in Oracle Database 10g. When a user drops a table, Oracle will place it in a Recycle Bin. Objects in the Recycle Bin will remain there until user decides to permanently remove them or the space pressure is placed on the tablespace containing the table. The recycle bin is a virtual container where all dropped objects reside. Users can look in the Recycle Bin and undrop the dropped table and its dependent objects.

The articles listed below help you in understanding the concepts,configuration,usage and known issues of the flashback drop:


Note.265254.1 Flashback Table Feature in Oracle Database 10g
Note.266477.1 Purge, Flashback Before Drop While Multiple Tables in the Recyclebin With Same Name
Note.265253.1 10g Recyclebin Features And How To Disable it( _recyclebin )
Note.433768.1 Invalid Object BIN$xxx In DBA_OBJECTS But None Exists in RECYCLEBIN

Flashback Table

Flashback Table is a new Oracle Database 10g feature that enables users to recover a table to a previous point in time. It provides a fast, online solution for recovering a table that has been accidentally modified or deleted by a user or application. In many cases, Flashback Table alleviates the need for administrators to perform more complicated point in time recovery operations. Even after a flashback, the data in the original table is not lost. You can later revert it back to the original state.

* provides fast recovery on a table(s) to a point in time in the past without restoring a backup.
* restores all data in a specified table to a previous point in time described by a timestamp or SCN. An exclusive DML lock is held on a table while it is being restored.
* performs the restore operation online.
* automatically restores all of the table attributes, such as indexes, triggers, and the likes that are necessary for an application to function with the flashed-back table.
* maintains any remote state in a distributed environment.
* maintains data integrity as specified by constraints.

The articles listed below help you in understanding the concepts,usage and known issues of the flashback table:

Note.246421.1 How to recover Table data Using the Flashback Table Feature
Note.270060.1 Use Flashback Table Feature and Resolve errors
Note.266536.1 What are the SELECT ANY TRANSACTION / FLASHBACK ANY TABLE Privileges ?
Note.1081777.1 Do DataPump Export/Import Utilities Work With Flashback Archived Tables?
Note.781112.1 How to flashback MVs and MV referred tables

Flashback Query

A database query, by default, always shows a consistent set of data containing most recently committed changes. With Flashback Query, introduced in Oracle9i, users are able to query a consistent version of the database as it was at some point in the past either by specifying a wall clock time or a System Change Number (SCN).

The articles listed below help you in understanding the concepts,usage and known issues of the flashback query:

Note.174425.1 Oracle9i Recovering lost data through Flashback Query
Note.204334.1 Parameters FLASHBACK_SCN And FLASHBACK_TIME Point In Time Export
Note.7159451.8 Bug 7159451 - Flashback query does not work against FGA / OLS tables
Note.5667658.8 Bug 5667658 - Wrong results / errors from flashback to SCN before segment shrink (affects MViews)


Flashback Versions

Flashback Versions Query is an extension to SQL that allows you to retrieve the different versions of rows in a given table that existed in a specific time interval. It returns a row for each version of the row that existed in the time interval you specify. For any given table, a new row version is created every time the COMMIT statement is executed. You specify the flashback versions query using the VERSIONS BETWEEN clause of the SELECT statement.

The articles listed below help you in understanding the concepts,usage and known issues of the flashback versions query :

Note.270270.1 Flashback Version Query & Flashback Transaction Query - Oracle 10G Enhancement
Note.268611.1 FLASHBACK VERSIONS QUERY GIVES ORA-600 [15201] ERROR
Note.1076598.1 VERSIONS_OPERATION not displayed in flashback version query using rowid after a delete

Flashback Transaction


Flashback Transaction Query provides a way for you to view all changes made to the database at the transaction level. When used in conjunction with Flashback Versions Query, it allows you to easily recover from user or application errors. It increases online diagnosability of problems in your database and performs analysis and audits of transactions.

Flashback Transaction Query shows all the resultant changes made by this transaction. In addition, compensating SQL statements are returned and can be used to undo changes made to all rows by this transaction. Using a precision tool like this, the DBA and application developer can precisely diagnose and correct logical problems in the database or application.

The articles listed below help you in understanding the concepts,usage and known issues of the flashback transaction query :


Note.317499.1 10G Oracle Flashback Transaction Query - Introduction and usage
Note.270270.1 Flashback Version Query & Flashback Transaction Query - Oracle 10G Enhancement
Note.332193.1 Querying Select Undo_sql From Flashback_transaction_query is slow
Note.5726687.8 Bug 5726687 - OERI 4147 querying FLASHBACK_TRANSACTION_QUERY
Note.4459574.8 Bug 4459574 - FLASHBACK_TRANSACTION_QUERY shows multi row INSERT as SELECT as only one row

Flashback Data Archive

A new database object, a flashback data archive is a logical container for storing historical information. It is stored in one or more tablespaces and tracks the history for one or more tables.The articles listed below help you in understanding the concepts,usage and known issues of the flashback data archive :

Note.470199.1 11g feature Flashback Data Archive Guide.
Note.1081777.1 Do DataPump Export/Import Utilities Work With Flashback Archived Tables?
Note.566593.1 Are Flashback Archive Tables Exported During Schema Export

Flashback & Dataguard

Here are a list of notes to which provide information of effective usage of flashback in a dataguard environment.

Note 416310.1 Reinstating a Physical Standby Using Backups Instead of Flashback
Note.805438.1 How To Open Physical Standby For Read Write Testing and Flashback
Note.838249.1 Physical Standby Read/Write Testing With Belated Flashback Database
Note.958557.1 How To Recover From A Drop/Truncate/Delete Table Done On Primary Using Flashback On A Standby Database
Note.824213.1 Effect of doing PITR (point in time recovery) / Flashback on PRIMARY when Physical Standby in place ORA-19906 ORA-19909 ORA-01110

Related Master Notes


Note 1116484.1 Master Note for Oracle Recovery Manager (RMAN)
Note 1096952.1 Master Note for Real Application Clusters (RAC) Oracle Clusterware and Oracle Grid Infrastructure
Note 1088018.1 Master Note for Oracle Database Corruption
Note.1101938.1 Master Note for Data Guard

Using My Oracle Support Effectively


Note 374370.1 New Customers Start Here
Note 736737.1 My Oracle Support - The Next Generation Support Platform
Note 730283.1 Get the most out of My Oracle Support
Note 747242.5 My Oracle Support Configuration Management FAQ
Note 868955.1 My Oracle Support Health Checks Catalog
Note 166650.1 Working Effectively With Global Customer Support
Note 199389.1 Escalating Service Requests with Oracle Support Services

Generic Links


Note 854428.1 Patch Set Updates for Oracle Products
Note 1061295.1 Patch Set Updates - One-off Patch Conflict Resolution
Note 881382.1 Critical Patch Update October 2009 Patch Availability Document for Oracle Products
Note 967472.1 Critical Patch Update January 2010 Patch Availability Document for Oracle Products
Note 1060989.1 Critical Patch Update April 2010 Patch Availability Document for Oracle Products
Note 756671.1 Oracle Recommended Patches -- Oracle Database
Note 268895.1 Oracle Database Server Patchset Information, Versions: 8.1. 7 to 11.2.0
Note 161549.1 Oracle Database Server and Networking Patches for Microsoft Platforms

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