For each tablespace that you want to redirect:. Expand the tablespace. In the Datafiles box, change the path to the new location.
To redirect the online redo logs, move the Online redo logs toggle key to the right, and then enter the full path for the new location. Click Save. Select the data that you want to restore:. To restore the database or individual tablespaces, select the Database check box and clear the Control file check box. To restore the control file, clear the Database check box and select the Control file check box.
To restore the log files, clear the Database check box. Select the database Recover to option. These options control how the archive files are applied to the data files. To recover to the latest backup job completion time, select Most recent backup. Did that answer your question? Yes, thank you for the explanation.
From one Dave to another, you are very generous in your thoughts We need more people in the world like you, who enjoy their work and are willing to assist others. Again thanks, David. Santa, is it really as easy to recover from a hot backup as running the RMAN command: Restore database; And what would be the complete command for Recovering to a specific point in time if all the arhcive logs are available?
So do the redo logs get backed up when you do a full backup of the database? Alex , Certainly you are correct. Thanks, hoinz I appreciate your input since I know very little about Oracle. Again Thanks for making this a lot easier, Sincerely David David. David, very sorry to hear of your family's tribulations. Thanks Ken, your heart felt concerns are greatly appreciated.
Red Flag This Post Please let us know here why this post is inappropriate. Close Box. Log In Come Join Us! Posting Guidelines Promoting, selling, recruiting, coursework and thesis posting is forbidden. NOTE: Do not run on-line backups during peak processing periods. Oracle will write complete database blocks instead of the normal deltas to redo log files while in backup mode. This will lead to excessive database archiving and even database freezes.
The DBA is then required to recover the database and apply all archived logs to the database. However, from Oracle 7. This normally saves a significant amount of database down time. From Oracle9i onwards, the following command can be used to take all of the datafiles out of hotbackup mode:. When a tablespace is in backup mode, Oracle will stop updating its file headers, but will continue to write to the data files. When in backup mode, Oracle will write complete changed blocks to the redo log files.
Normally only deltas change vectors are logged to the redo logs. This is done to enable reconstruction of a block if only half of it was backed up split blocks.
Because of this, one should notice increased log activity and archiving during on-line backups. RMAN ships with the database server and doesn't require a separate installation.
RMAN can do off-line and on-line database backups. Here are the command line arguments:. The biggest advantage of RMAN is that it only backup used space in the database. RMAN doesn't put tablespaces in backup mode, saving on redo generation overhead. RMAN will re-read database blocks until it gets a consistent image of it.
Look at this simple backup example. The examples above are extremely simplistic and only useful for illustrating basic concepts. By default Oracle uses the database controlfiles to store information about backups. Note: RMAN cannot write image copies directly to tape. One needs to use a third-party media manager that integrates with RMAN to backup directly to tape. Alternatively one can backup to disk and then manually copy the backups to tape.
One can backup archived log files using RMAN or any operating system backup utility. Incremental backups are not allowed. Blocks that are marked media corrupt are not accessible to users until recovery is complete. Any attempt to use a block undergoing media recovery results in an error message indicating that the block is media corrupt. In such cases, datafile media recovery is the best solution.
Block media recovery is not a replacement for traditional datafile media recovery, but a supplement to it. In most cases, Oracle marks a block as media corrupt, invalidates the block in the instances or all enabled instances in an Oracle Real Application Clusters configuration , and then writes it to disk when the corruption is first encountered.
No subsequent read of the block will be successful until the block is recovered. You can only perform block recovery on blocks that are marked corrupt. This corrupt status effectively takes the block offline in all database instances and prevents user access during recovery.
Block media recovery is most useful for data losses that affect specific blocks. Typically, these types of block corruption are reported in these locations:.
The alert. Like datafile media recovery, block media recovery cannot survive a missing or inaccessible archived log. Nevertheless, block media recovery can survive gaps in the redo stream if the missing or corrupt redo records do not affect the blocks being recovered. Whereas datafile recovery requires an unbroken series of redo changes from the beginning of recovery to the end, block media recovery only requires an unbroken set of redo changes for the blocks being recovered.
Note: Each block is recovered independently during block media recovery, so recovery may be successful for a subset of blocks. When RMAN first detects missing or corrupt redo records during block media recovery, it does not immediately signal an error because the block undergoing recovery may become a newed block later in the redo stream. When a block is newed all previous redo for that block becomes irrelevant because the redo applies to an old incarnation of the block.
For example, Oracle can new a block when users delete all the rows recorded in the block or drop a table. Assume that media recovery is performed on block 13 as depicted in Figure After block recovery begins, RMAN discovers that change is missing.
RMAN does not terminate recovery in the hope that block 13 will be newed later in the redo stream. At this point, Oracle formats block 13 as a new block. The command takes backups and copies of the primary database's files and uses them to create a new database.
A test database is especially useful if your production database must maintain high availability. Generates a new, unique database identifier for the duplicate database.
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