A database restore might be necessary when the data area or the log area is damaged, to recover from a logical error, or to copy the database.
Perform a restore operation immediately after your first full backup to understand the process.
Restore Types
Oracle restores fall into the following main categories:
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Database restore: This is a restore of all database files, the control file, and the server parameter file.
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Database subset: This is a combination of a restore of any of the following files:
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Only archive logs
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Oracle control file
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Individual data files and tablespaces
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Database archived redo logs
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Restore Destinations
You can restore to the following destinations:
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In-place restore
When you restore a database in place, you restore it to the same database on the same client from which the database was backed up.
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Out-of-place restore
When you restore a database out of place, you can restore it to any one of the following destinations:
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A different client than the one from which the database was backed up
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A different database on the same client from which the database was backed up
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Recovery Options
After the restore, you can recover the database to a point other than the current time, if the current database is inconsistent.
When you choose the option to recover from the latest backup time or from the latest SCN with a secondary copy, the software only considers the time or SCN from the latest job available on the secondary copy, even when the primary copy or other copies have a more recent backup job.
Database Clones
You can use the cloning feature to do the following:
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Duplicate large databases in a short amount of time
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Create test environments
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Retrieve data quickly without intensive resource use on a production environment
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Alleviate the load on production servers
You can create a clone from an existing data and log volume full backup. When you create a clone, you must specify the reservation period. The system automatically shuts down the clone database and frees up all resources (including the snapshot clones on the storage array and ASM disk groups) when the reservation period expires.
Schedule clones to run periodically so that the clones are refreshed on a regular basis.