FLASHBACK TABLE → Purpose Use the FLASHBACK TABLE statement to restore an earlier state of a table in the event of … parameters. You cannot roll back a FLASHBACK TABLE statement. However, you can issue another FLASHBACK TABLE … the current SCN before issuing a FLASHBACK TABLE clause. See Also: FLASHBACK DATABASE for information
FLASHBACK DATABASE → Purpose Use the FLASHBACK DATABASE statement to return the database to a past time or system change … . Following a FLASHBACK DATABASE operation, in order to have write access to the flashed back … Backup and Recovery User's Guide for more information on FLASHBACK DATABASE Prerequisites You must … database must have been put in
ALTER FLASHBACK ARCHIVE → Purpose Use the ALTER FLASHBACK ARCHIVE statement for these operations: Designate a flashback data … archive as the default flashback data archive for the system Add a tablespace for use by the … flashback data archive Change the quota of a tablespace used by the flashback data archive Remove a
CREATE FLASHBACK ARCHIVE → Purpose Use the CREATE FLASHBACK ARCHIVE statement to create a flashback data archive, which … objects. A flashback data archive consists of multiple tablespaces and stores historic data from all … transactions against tracked tables. The data is stored in internal history tables. Flashback data … . Historical
DROP FLASHBACK ARCHIVE → Purpose Use the DROP FLASHBACK ARCHIVE clause to remove a flashback data archive from the system … . This statement removes the flashback data archive and all the historical data in it, but does not … drop the tablespaces that were used by the flashback data archive. Prerequisites You must have the … FLASHBACK
Flashback Database → is accessible through the RMAN command and SQL statement FLASHBACK DATABASE. You can use either … command to quickly recover the database from logical data corruptions or user errors. Flashback … database to its state at a time in the recent past. Flashback Database is much faster than point-in-time … changes from the archived
Flashback Database → Oracle Database includes the following logical flashback features: Oracle Flashback Query You can … Database Advanced Application Developer's Guide explains how to use this feature. Oracle Flashback … Database Advanced Application Developer's Guide explains how to use this feature. Oracle Flashback … this feature.
Monitoring Flashback Database → When you use Flashback Database to rewind a database to a past target time, Flashback Database … determines which blocks changed after the target time and restores them from the flashback logs. This is … called the restore phase. After this phase completes, Flashback Database then uses redo logs to … reapply changes
Disabling Flashback Database Logging → On a database instances that is either in mount or open state, issue the following command: ALTER DATABASE FLASHBACK OFF;
Prerequisites of Flashback Table → To use the Flashback Table feature on one or more tables, use the FLASHBACK TABLE SQL statement … with a target time or SCN. You must have the following privileges to use the Flashback Table feature … : You must have been granted the FLASHBACK ANY TABLE system privilege or you must have the FLASHBACK
Oracle Flashback Technology → As explained in Oracle Database Concepts, Oracle Flashback Technology complements your physical … . Specifically, you can use the various features of Oracle Flashback to view past states of data and … , flashback features are more efficient and less disruptive than media recovery in most situations in which they apply.
Logical Flashback Features → Most of the flashback features of Oracle operate at the logical level, enabling you to view and … manipulate database objects. The logical-level flashback features of Oracle do not depend on RMAN and … are available whether or not RMAN is part of your backup strategy. Except for Oracle Flashback Drop … , the logical flashback
Flashback Database Window → The range of SCNs for which there is currently enough flashback log data to support the FLASHBACK … DATABASE command is called the flashback database window. The flashback database window cannot extend … further back than the earliest SCN in the available flashback logs. Note: Some database operations
Limitations of Flashback Database → Because Flashback Database works by undoing changes to the data files that exist at the moment when … you run the command, it has the following limitations: Flashback Database can only undo changes to … accidental deletion of data files. You cannot use Flashback Database to undo a shrink data file … then later restore and recover
Using Flashback Database → This section describes the basic commands for Flashback Database. It also lists guidelines to ensure optimal performance of Flashback Database.
About Flashback Drop → Flashback Drop reverses the effects of a DROP TABLE operation. Flashback Drop is faster than other … . You can query objects in the recycle bin, just as you can query other objects. A flashback … perform Flashback Drop, the objects are generally all retrieved together. When you restore a table from
Prerequisites of Flashback Drop → The following list summarizes the user privileges required for the operations related to Flashback … , placing it in the recycle bin. FLASHBACK TABLE... TO BEFORE DROP Privileges for this statement are … tied to the privileges for DROP. That is, any user who can drop an object can perform Flashback Drop to … FLASHBACK
Prerequisites of Flashback Database → To use the FLASHBACK DATABASE command to return your database contents to points in time within the … flashback window, your database must be configured for flashback logging as described in … \"Understanding Flashback Database, Restore Points and Guaranteed Restore Points\". To return the database to … Normal
Enabling Flashback Database → Follow these are the steps to enable Flashback Database. To enable flashback logging: Ensure the … . Optionally, set the DB_FLASHBACK_RETENTION_TARGET to the length of the desired flashback window in … DB_FLASHBACK_RETENTION_TARGET is set to 1 day (1440 minutes). Enable the Flashback Database feature for the whole database
Recovering Tables Using Oracle Flashback Table → Recovering Tables Using Oracle Flash back Table Oracle Flashback Table enables you to restore a … , Oracle Flashback Table eliminates the need for you to perform more complicated point-in-time recovery … operations. Oracle Flashback Table: Restores all data in a specified table to a previous point in time … specified between a
FLASHBACK DATABASE → Purpose Use the FLASHBACK DATABASE command to rewind the database to a target time, SCN, or log … exist when you run the command. Flashback can fix logical failures, but not physical failures. Thus … . FLASHBACK DATABASE is usually much faster than a RESTORE operation followed by point-in-time recovery … , because the time needed
Performing a Flashback Table Operation → In this scenario, assume that you want to perform a flashback of the hr.temp_employees table after … a user made some incorrect updates. The perform a flashback of temp_employees: Connect SQL*Plus to … the target database and identify the current SCN. You cannot roll back a FLASHBACK TABLE statement … , but you can issue another
Performing a Flashback Drop Operation → Use the FLASHBACK TABLE... TO BEFORE DROP statement to recover objects from the recycle bin. You … and drop hr.employee_demo. You decide to use FLASHBACK TABLE to retrieve the dropped object. To … can also use Flashback Query on tables in the recycle bin, but only by using the recycle bin name … bin. Retrieve the dropped table.
Performing a Flashback Database Operation → This section presents a basic technique for performing a flashback of the database, specifying the … most recent OPEN RESETLOGS, see \"Rewinding an OPEN RESETLOGS Operation with Flashback Database\". By … default, an SCN used in a FLASHBACK DATABASE command refers to an SCN in the direct ancestral path … Incarnation Branch\".
TO BEFORE SEQUENCE integer THREAD integer Specifies a redo log sequence number and thread as an upper… → most recent OPEN RESETLOGS. Note: FLASHBACK DATABASE can only return the database to a point before … to convert the time to the current format, for example, FLASHBACK DATABASE TO TIME 'SYSDATE-7'. Query … can flash back. Examples Example 2-87 FLASHBACK DATABASE to a Specific SCN Assume that you inserted … query the earliest SCN
Table 2-8 How FLASHBACK DATABASE Responds to Data File Status Changes → The earliest SCN that can be used for a Flashback Database operation depends on the setting of the … DB_FLASHBACK_RETENTION_TARGET initialization parameter, and on the actual retention of flashback … NOLOGGING Operations on Flashback Database When using FLASHBACK DATABASE with a target time at which a … Flashback
Using Flashback Drop and Managing the Recycle Bin → Flashback Drop, and the FLASHBACK TABLE statement is used to restore the table. Before discussing the … use of the FLASHBACK TABLE statement for this purpose, it is important to understand how the
Performing Flashback Database with SQL*Plus → Oracle Flashback Database returns your entire database to a previous state without requiring you to … restore files from backup. The SQL*Plus FLASHBACK DATABASE command performs the same function as … the RMAN FLASHBACK DATABASE command: it returns the database to a prior state. Flashback Database … requires you
Starting and Configuring RMAN and Flashback Database → Part II Starting and Configuring RMAN and Flashback Database The chapters in this part explain the … Environment: Advanced Topics\" Chapter 7, \"Using Flashback Database and Restore Points\"
Rewinding a Table with Flashback Table → Flashback Drop relies on a mechanism called the recycle bin, which the database uses to manage … Developer's Guide to learn how to use the logical flashback features \"Understanding Flashback … to use Flashback Database, and on the related restore points feature Rewinding a Table with … Flashback
7 Using Flashback Database and Restore Points → This chapter explains Flashback Database, restore points. This chapter discusses configuring … contains the following topics: Understanding Flashback Database, Restore Points and Guaranteed … Restore Points Logging for Flashback Database and Guaranteed Restore Points Prerequisites for Flashback … Database and
Rewinding a Database with Flashback Database → This section explains the most common scenario for using Flashback Database to reverse unwanted changes to your database.
Rewinding a Database with Flashback Database → You can use the Oracle Flashback Database to rewind the whole database to a past time. Unlike media … RMAN FLASHBACK DATABASE command, your database must have been previously configured to generate … flashback logs. This configuration task is described in \"Flashback Database\". Flashback Database works
flashback logfile sync → Waits for flashback database data to be written to disk. Wait Time: Includes RVWR writing the … flashback database data and posting this process Parameters: None
Overview of User-Managed Media Recovery → This section provides an overview of recovery with SQL*Plus. This section contains the following topics: About User-Managed Restore and Recovery Automatic Recovery with the RECOVER Command Recovery When Archived Logs Are in the Default Location Recovery When Archived Logs Are in a Nondefault Location Recovery Cancellation Parallel Media Recovery
About User-Managed Restore and Recovery → Typically, you restore a file when a media failure or user error has damaged or deleted multiple data files. In a user-managed restore operation, you use an operating system utility to restore a backup of the file. If a media failure affects data files, then the recovery procedure depends on: The archiving mode of the database: ARCHIVELOG or NOARCHIVELOG The type of media failure The files affected
Performing Complete Database Recovery → Typically, media recovery is limited by data block reads and writes. Parallel recovery attempts to use all of the available I/O bandwidth of the system to improve performance. Unless there is a system I/O bottleneck or poor asynchronous I/O support, parallel recovery is likely to improve performance of recovery. To override the default behavior of performing parallel recovery, use the SQL*Plus RECOVER
Performing Closed Database Recovery → also use Flashback Database, but this procedure affects all data files and returns the entire database
Table 29-5 Media Recovery Solutions → If You Suspect... Then... Missing or misnamed archived redo logs Determine whether you entered the correct file name. If you did, then check whether the log is missing from the operating system. If it is missing, and if you have a backup, then restore the backup and apply the log. If you do not have a backup, then if possible perform incomplete recovery up to the point of the missing log. ORA-1113
Performing Trial Recovery → When problems such as stuck recovery occur, you have a difficult choice. If the block is relatively unimportant, and if the problem is isolated, then it is better to corrupt the block. But if the problem is not isolated, then it may be better to open the database with the RESETLOGS option. Because of this situation, Oracle Database supports trial recovery. A trial recovery applies redo in a way similar
Using Normal and Guaranteed Restore Points → This section describes the various commands and monitoring capabilities you use with normal and guaranteed restore points.
Troubleshooting Media Recovery → This section describes how to troubleshoot user-managed media recovery, that is, media recovery performed without using Recovery Manager (RMAN). This section includes the following topics: About User-Managed Media Recovery Problems Investigating the Media Recovery Problem: Phase 1 Trying to Fix the Recovery Problem Without Corrupting Blocks: Phase 2 Deciding Whether to Allow Recovery to Mark as Corrupt
Table 29-4 Media Recovery Problems → Problem Description Missing or misnamed archived log Recovery stops because the database cannot find the archived log recorded in the control file. When you attempt to open the database, error ORA-1113 indicates that a data file needs media recovery. This error commonly occurs because: You are performing incomplete recovery but failed to restore all needed data file backups. Incomplete recovery stopped
Corrupted archived logs Logs may be corrupted while they are stored on or copied between storage systems.… → The database signals an internal error when applying the redo. This problem can be caused by an Oracle Database bug. If checksum verification is not being used, then the errors can also be caused by corruptions to the redo or data blocks. Corrupted archived logs Logs may be corrupted while they are stored on or copied between storage systems. If DB_BLOCK_CHECKSUM is enabled, then the database usually
Recovery Cancellation → If you start media recovery and must then interrupt it, then either enter CANCEL when prompted for a redo log file, or use your operating system's interrupt signal if you must terminate when recovering an individual data file, or when automated recovery is in progress. After recovery is canceled, you can resume it later with the RECOVER command. Recovery resumes where it left off when it was canceled.
Performing Open Database Recovery → It is possible for a media failure to occur while the database remains open, leaving the undamaged data files online and available for use. Damaged data files—but not the tablespaces that contain them—are automatically taken offline if the database writer cannot write to them. If the database writer cannot open a data file, an error is still returned. Queries that cannot read damaged files return
Performing Incomplete Database Recovery → Typically, you perform database point-in-time recovery (DBPITR) in the following situations: You want to recover the database to an SCN before a user or administrative error. The database contains corrupt blocks. Complete database recovery failed because all necessary archived redo logs were not available. You are creating a test database or a reporting database from production database backups. If
Allowing Recovery to Corrupt Blocks: Phase 4 → If you decide to allow recovery to proceed despite block corruptions, then run the RECOVER command with the ALLOW n CORRUPTION clause, where n is the number of allowable corrupt blocks. To allow recovery to corrupt blocks: Ensure that all normal recovery preconditions are met. For example, if the database is open, then take tablespaces offline before attempting recovery. Run the RECOVER command as
Understanding Flashback Database, Restore Points and Guaranteed Restore Points → Oracle Flashback Database and restore points are related data protection features that enable you … similar to database point-in-time recovery (DBPITR). Flashback Database and restore points are not only … -created. Flashback Database also provides an efficient alternative to rebuilding a failed primary … points provide capabilities
Logging for Flashback Database with Guaranteed Restore Points Defined → If you enable Flashback Database and define one or more guaranteed restore points, then the … database performs normal flashback logging. In this case, the recovery area retains the flashback logs … guaranteed restore point. Flashback logs are not deleted in response to space pressure if they are … required to
Prerequisites for Flashback Database and Guaranteed Restore Points → To ensure successful operation of Flashback Database and guaranteed restore points, you must first … set several key database options. Flashback Database Configure the following database settings … before enabling Flashback Database: Your database must be running in ARCHIVELOG mode, because archived … logs are used in the Flashback
Configuring the Environment for Optimal Flashback Database Performance → Maintaining flashback logs imposes comparatively limited overhead on an database instance. Changed … blocks are written from memory to the flashback logs at relatively infrequent, regular intervals, to … Flashback Database enabled, Oracle recommends the following: Use a fast file system for your fast … the fast recovery area,
29 Performing User-Managed Database Flashback and Recovery → This chapter describes how to restore and recover a database and use the flashback features of … : Performing Flashback Database with SQL*Plus Overview of User-Managed Media Recovery Performing Complete
Table 29-1 User-Managed Restore Operations → If You Lose... Then... Data files in the SYSTEM tablespace or data files with active undo segments The database automatically shuts down. If the hardware problem is temporary, then fix it and restart the database. Usually, crash recovery recovers lost transactions. If the hardware problem is permanent, then restore the data files from backups and recover the database as described in \"Performing Closed
Automatic Recovery with the RECOVER Command → When using SQL*Plus to perform media recovery, the easiest strategy is to perform automatic recovery with the SQL*Plus RECOVER command. Automatic recovery initiates recovery without manually prompting SQL*Plus to apply each individual archived redo log. When using SQL*Plus, you have the following options for automating the application of the default file names of archived redo logs needed during recovery:
Performing Cancel-Based Incomplete Recovery → In cancel-based recovery, recovery proceeds by prompting you with the suggested file names of archived redo log files. Recovery stops when you specify CANCEL instead of a file name or when all redo has been applied to the data files. To perform cancel-based recovery: Follow Step 1 through Step 8 in \"Performing Closed Database Recovery\". Begin cancel-based recovery by issuing the following command
Performing Time-Based or Change-Based Incomplete Recovery → This section describes how to specify an SCN or time for the end point of recovery. If your database is affected by seasonal time changes (for example, daylight savings time), then you may experience a problem if a time appears twice in the redo log and you want to recover to the second, or later time. To handle time changes, perform cancel-based or change-based recovery. To perform change-based or
Table 29-6 Guidelines for Allowing Recovery to Permit Corrupt Blocks → After you have done these investigations, you can follow the guidelines in Table 29-6 to decide whether to allow recovery to permit corrupt blocks. Table 29-6 Guidelines for Allowing Recovery to Permit Corrupt Blocks If the Problem Is... and the Block Is... Then... Not isolated You should probably open the database with the RESETLOGS option. This response is important for stuck recovery problems,
Logging for Guaranteed Restore Points with Flashback Logging Disabled → Assume that you create a guaranteed restore point when logging for Flashback Database is disabled … point, the database stores an image of the block before the modification in the flashback logs. Thus … , the flashback logs preserve the contents of every changed data block at the time that the … or a subsequent flashback
Flashback Writer (RVWR) Behavior with I/O Errors → When flashback is enabled or when there are guaranteed restore points, the background process RVWR … writes flashback data to flashback database logs in the fast recovery area. If RVWR encounters an I … : On a primary database, Oracle Database automatically disables Flashback Database while the database … protection