Oracle RMAN Reset Database After RESETLOGS Recovery

calendar Jan 9, 2026 / · 6 min read · Oracle Database RMAN Database Recovery Backup and Restore Recovery Catalog Database Administration Incomplete Recovery RESETLOGS  ·
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Oracle RMAN Reset Database After RESETLOGS Recovery

Purpose

The RESET DATABASE command in Oracle Recovery Manager (RMAN) notifies the recovery catalog that a new database incarnation has been created after opening the database with the RESETLOGS option. This command is essential for maintaining synchronization between the RMAN repository and the target database following incomplete recovery, point-in-time recovery, or recovery using a backup control file.

Original Code

1-- Reset the catalog after a restlogs on the target
2reset database;

Breakdown of Code

The command consists of two simple keywords that perform a critical function:

  • RESET DATABASE: This command informs RMAN that the database has been opened with ALTER DATABASE OPEN RESETLOGS, creating a new database incarnation
  • The command must be executed at the RMAN prompt while connected to the target database
  • RMAN must be connected to both the target database and the recovery catalog for proper synchronization

When to Use This Command

After RESETLOGS Operations

You must issue the RESET DATABASE command when you open a target database using the SQL statement ALTER DATABASE OPEN RESETLOGS but do not use the RMAN equivalent command. If you execute ALTER DATABASE OPEN RESETLOGS through RMAN instead of SQL, RMAN automatically resets the database, eliminating the need for this manual command.

Recovery Scenarios

The command is required in these specific situations:

  • After incomplete recovery to a specific point in time
  • Following recovery using a backup control file
  • When restoring and recovering to an SCN before the current RESETLOGS timestamp
  • After using FLASHBACK DATABASE to rewind to an orphaned database incarnation

Understanding Database Incarnations

What is a Database Incarnation

A database incarnation is created whenever you open the database with the RESETLOGS option. The RESETLOGS operation archives current online redo logs, erases their contents, resets the log sequence number to 1, and assigns a new RESETLOGS SCN and timestamp to all datafiles and redo logs.

Incarnation Types

Database incarnations fall into several categories:

  • Current Incarnation: The incarnation in which the database is currently operating and generating redo
  • Parent Incarnation: The incarnation from which the current incarnation branched following an OPEN RESETLOGS operation
  • Ancestor Incarnation: The parent of a parent incarnation
  • Sibling Incarnation: Two incarnations sharing a common ancestor but neither is an ancestor of the other

Why This Command is Critical

Preventing Recovery Catalog Errors

If you issue ALTER DATABASE OPEN RESETLOGS without resetting the database in RMAN, the recovery catalog cannot access the target database because it cannot distinguish between a legitimate RESETLOGS command and an accidental restore of an old control file. This protection mechanism prevents data corruption and ensures recovery integrity.

Maintaining Backup History

The RESET DATABASE command directs RMAN to create a new database incarnation record in the recovery catalog . This new incarnation record indicates the current incarnation, and RMAN associates all subsequent backups and archived logs with this new database incarnation.

Complete Recovery Example

Here is a typical workflow using the RESET DATABASE command:

 1-- Step 1: Connect to target and catalog
 2RMAN> CONNECT TARGET sys/password@target
 3RMAN> CONNECT CATALOG rman/password@catalog
 4
 5-- Step 2: Perform incomplete recovery
 6RMAN> STARTUP MOUNT;
 7RMAN> RUN {
 8  SET UNTIL SCN 154876;
 9  RESTORE DATABASE;
10  RECOVER DATABASE;
11}
12
13-- Step 3: Open database with RESETLOGS (using SQL, not RMAN command)
14SQL> ALTER DATABASE OPEN RESETLOGS;
15
16-- Step 4: Reset the database in RMAN catalog
17RMAN> RESET DATABASE;
18
19-- Step 5: Resynchronize the catalog
20RMAN> RESYNC CATALOG;

Resetting to Previous Incarnations

Advanced Use Case

The RESET DATABASE TO INCARNATION command allows you to specify that SCNs should be interpreted in the context of a specific database incarnation. This is useful when you need to undo the effects of a RESETLOGS operation by restoring backups from a prior incarnation.

Procedure for Resetting to Old Incarnation

 1-- Step 1: List available incarnations
 2RMAN> LIST INCARNATION OF DATABASE;
 3
 4-- Step 2: Reset to desired incarnation
 5RMAN> RESET DATABASE TO INCARNATION 2;
 6
 7-- Step 3: Restore and recover from that incarnation
 8RMAN> RUN {
 9  RESTORE DATABASE UNTIL SCN 154876;
10  RECOVER DATABASE UNTIL SCN 154876;
11}
12
13-- Step 4: Open with RESETLOGS to create new incarnation
14RMAN> ALTER DATABASE OPEN RESETLOGS;

Key Points

  • The command requires RMAN to be connected to both target database and recovery catalog
  • In NOCATALOG mode, the target database must be mounted with a control file containing the specified incarnation record
  • Using the RMAN command ALTER DATABASE OPEN RESETLOGS (not the SQL statement) automatically resets the database
  • The RESET DATABASE TO INCARNATION command is persistent across RMAN sessions when using NOCATALOG mode
  • Always resynchronize the recovery catalog after resetting the database using RESYNC CATALOG

Best Practices

Catalog Maintenance

Resynchronize your recovery catalog regularly, especially in ARCHIVELOG mode, because the catalog is not updated automatically when redo log switches occur. The frequency should be proportional to your archive log generation rate.

Backup Strategy

After opening with RESETLOGS in Oracle 10g and later, you do not need to perform a full database backup before resuming normal operations. The Simplified Recovery Through RESETLOGS (SRR) feature allows RMAN to use backups from parent incarnations for recovery and incremental backups.

Archive Log Format

Ensure your LOG_ARCHIVE_FORMAT parameter includes the %r (resetlogs ID) specification to distinguish archive logs from different incarnations. This is critical for recovery through RESETLOGS operations.

Insights

The RESET DATABASE command serves as a crucial bridge between SQL-level database operations and the RMAN recovery catalog. Without this synchronization, RMAN's sophisticated backup and recovery features become unavailable, potentially leaving your database vulnerable during recovery scenarios.

Understanding database incarnations and proper use of the RESET DATABASE command enables database administrators to perform complex recovery operations, including recovering to points before RESETLOGS operations and managing multiple incarnation branches. This flexibility is invaluable in disaster recovery and testing scenarios where multiple recovery paths may need to be explored.

References

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