Oracle database backup is an important role for oracle DBA. Physical Backups Oracle database physical backup includes of backing up the physical files as Datafiles Archived redo logs Control files Network files (tnsnames.ora,listener.ora,sqlnet.ora) Parameter file Physical backups are made on the disk or on the tape devices. Logical Backups Oracle database logical backup made using [...]
Published by Paresh Sarma //
In some scenarios, if a user accidentally deleted rows of a table and as a DBA you have to recover the table to point in time . How you can recover the rows without using more time -consuming tablespace point-in-time recovery operation? Flashback Table allows us to recover one or more tables to specific point [...]
Published by Paresh Sarma //
How Recovery Manager (RMAN) perform backup of target database ? Following is an example for taking backup of target database with RMAN.For easy understanding,assume target database orcltarget01 and catalog database as orclrman. Simple steps to backup the database with Recovery Manager Steps -I : Execute the following command windows C:\> set ORACLE_SID=orcltarget01 Steps -II : [...]
Published by Paresh Sarma //
Recovery Manager configuration is very simple and straightforward process.Two ways we can configure RMAN backup. Command line version Web-based GUI through EM database control There are many parameters of RMAN can control for better utilization and performance of backup and recovery process.The parameters can be configured through Oracle Enterprise Manager or RMAN command line option. [...]
Published by Paresh Sarma //
Instance failure prevents the synchronization of the database’s datafiles and control file before the instance is shutdown. Oracle automatically recovers the instance failure when starting up the database with the STARTUP command. The main purpose of the instance failure is to bring the control file and database file to the same SCN. Instance recover occurs [...]
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Flashback Drop is an new features of Oracle 10g features. With Flashback Drop we can restore a dropped table easily without using tablespace point-in-time recovery. Tablespace point-in-time recovery is an time consuming process and had the side effect of losing work from other transactions that occurred within the same tablespace after the table was dropped. [...]
Published by Paresh Sarma //
Flashback Query features introduces in Oracle 9i. This features allows us to view the contents of a table as it existed at some point in the recent past. Flashback Query uses the “AS OF TIMESTAMP” clause in the standard SELECT statement.We can specify the timestamp as any valid expression that evaluates to a date or [...]
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Database restore is just opposite of our backup process.The backup file from disk or other media is copied back to their original location. when we need to do database restore After a media failure occurs When database point in time recovery to be done Database Recovery There is a change of data in the backup [...]
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As an Oracle DBA , Recover database and maintain high availability is your prime job. Some day you my faced a scenario where all your control files and online redo log files are lost and you have to recover your database as early as possible. In this section we will learn how to overcome such [...]
Published by Paresh Sarma //
The process of solve any type of database failures, quickly and without data loss and keep database high available is called database recovery.The main elements of database recovery is the most recent database backup. If you maintains database backup efficiently , then database recovery is very straight forward process. The components and technologies of database [...]
Published by Paresh Sarma //
