RESET DATABASE

Syntax

reset::=

Description of the illustration reset.gif

Purpose

To reset the incarnation of the target database in the RMAN repository, which means to do either of the following actions:

Inform RMAN that the SQL statement ALTER DATABASE OPEN RESETLOGS has been executed and that a new incarnation of the target database has been created. Note that if you run the RMAN command ALTER DATABASE OPEN RESETLOGS (not the SQL statement with the same keywords), then RMAN resets the target database automatically so that you do not have to run RESET DATABASE. By resetting the database, RMAN considers the new incarnation as the current incarnation of the database.
To reset the database to a previous incarnation. Typically, you would reset the incarnation when performing incomplete recovery to a point before a RESETLOGS operation, or when attempting to undo the affects of a RESETLOGS by restoring backups taken before a RESETLOGS.

Restrictions and Usage Notes

Execute RESET DATABASE only at the RMAN prompt.
You must be connected to the target database.
A recovery catalog connection is optional. Unlike in catalog mode, RESET DATABASE in nocatalog mode changes the incarnation only for the current RMAN session.
You must issue a RESET DATABASE command before you can use RMAN with a target database that has been opened with the SQL statement ALTER DATABASE OPEN RESETLOGS option. If you do not, then RMAN refuses to access the recovery catalog because it cannot distinguish between a RESETLOGS operation and an accidental restore of an old control file. The RESET DATABASE command informs RMAN that you issued a RESETLOGS command.
If RMAN is connected NOCATALOG, then you can only specify TO INCARNATION if the database is mounted and the control file contains a record of the prior incarnation. If you do not run RESET DATABASE, RMAN recovers to the last incarnation recorded in the control file.
If RMAN is connected in CATALOG mode, then you can specify TO INCARNATION when the database is mounted. If database is mounted, however, then the control file must have a record of the prior incarnation.

Keywords and Parameters

Syntax Element	Description
`TO` `INCARNATION` `primary_key`	Changes the current incarnation to an older incarnation. Specify the primary key of the `DBINC` record for the database incarnation. Run LIST `INCARNATION` `OF` `DATABASE` to obtain possible key values. After you issue `RESET` `DATABASE` `TO` `INCARNATION`, then you can run RMAN commands such as `RESTORE` and `RECOVER`.

Examples

Resetting RMAN to a Previous Incarnation in NOCATALOG Mode: Example In NOCATALOG mode, you must mount a control file that knows about the incarnation that you want to recover. The following scenario makes an old incarnation of database trgt current again:

CONNECT TARGET / NOCATALOG

# step 1: start and mount a control file that knows about the incarnation to which
# you want to return. if the current control file does not know about it, then
# you must restore an older control file
STARTUP NOMOUNT;
RESTORE CONTROLFILE UNTIL TIME 'SYSDATE-250';
ALTER DATABASE MOUNT;

# step 2: obtain the primary key of old incarnation
LIST INCARNATION OF DATABASE trgt;

List of Database Incarnations
DB Key  Inc Key DB Name  DB ID            STATUS   Reset SCN  Reset Time
------- ------- -------- -------------    -------  ---------- ----------
1       2       TRGT     1334358386       PARENT   154381     OCT 30 2001 16:02:12
1       116     TRGT     1334358386       CURRENT  154877     OCT 30 2001 16:37:39

# step 3: in this example, reset database to incarnation key 2
RESET DATABASE TO INCARNATION 2;

# step 4: restore and recover the database to a point before the RESETLOGS
RESTORE DATABASE UNTIL SCN 154876;
RECOVER DATABASE UNTIL SCN 154876;

# step 5: make this incarnation the current incarnation and then list incarnations:
ALTER DATABASE OPEN RESETLOGS;
LIST INCARNATION OF DATABASE trgt;

List of Database Incarnations
DB Key  Inc Key DB Name  DB ID            STATUS  Reset SCN  Reset Time
------- ------- -------- ---------------- ------- ---------- ----------
1       2       TRGT     1334358386       PARENT  154381     OCT 30 2001 16:02:12
1       116     TRGT     1334358386       PARENT  154877     OCT 30 2001 16:37:39
1       311     TRGT     1334358386       CURRENT 154877     AUG 13 2002 17:17:03

Resetting the Database After Incomplete Recovery: Example

This example assumes that an incomplete recovery or recovery with a backup control file was performed in NOCATALOG mode. Later, RMAN is started in CATALOG mode, but the RESYNC command fails because the incarnation has not been reset in the catalog.

% rman target / catalog rman/rman@catdb

Recovery Manager: Release 10.1.0.2.0 - Production

Copyright (c) 1995, 2003, Oracle.  All rights reserved.

connected to target database: TRGT (DBID=1334531173)
connected to recovery catalog database

RMAN> RESYNC CATALOG;

RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03009: failure of resync command on default channel at 11/01/2001 12:00:43
RMAN-20003: target database incarnation not found in recovery catalog

RMAN> RESET DATABASE;

new incarnation of database registered in recovery catalog
starting full resync of recovery catalog
full resync complete