RESYNC

Syntax

Text description of the illustration resync.gif

Purpose

To perform a full resynchronization of the recovery catalog.

Resynchronizations can be full or partial. When full, RMAN updates all changed records for the physical schema: datafiles, tablespaces, redo threads, and online redo logs. If the database is open, RMAN also obtains data about rollback segments. When partial, RMAN reads the current control file to update data, but does not resynchronize metadata about the physical schema or rollback segments.

When resynchronizing, RMAN creates a snapshot control file in order to obtain a read-consistent view of the control file, then updates the catalog with any new information from the snapshot. The RESYNC CATALOG command updates the classes or records described in the following table.

Record Type	Description
Log history	Records that are created whenever a log switch occurs. Note that log history records describe an online log switch, not a log archival.
Archived redo logs	Records associated with archived logs that were created by archiving an online redo log, copying an existing archived redo log, or restoring backups of archived redo logs.
Backups	Records associated with backup sets, backup pieces, backup set members, proxy copies, and image copies.
Physical schema	Records associated with datafiles and tablespaces. If the target database is open, then rollback segment information is also updated.

RMAN automatically executes a full or partial resynchronization as needed when you execute RMAN commands, so long as the control file is mounted and the recovery catalog database is available at command execution. RMAN reads the current control file and does not resynchronize metadata about the physical schema unless it determines that this information has changed. If RMAN does detect a change, then it performs a full resynchronization.

Use RESYNC CATALOG to perform manual full resynchronizations when:

• The recovery catalog is unavailable when you issue any of the commands that automatically perform a resynchronization.
• You are running in ARCHIVELOG mode, since the catalog is not updated automatically when a log switch occurs or when an online redo log is archived.
• You have made changes to the physical structure of the target database such as adding or dropping a tablespace. As with archive operations, the recovery catalog is not updated automatically when the physical schema changes.

Restrictions and Usage Notes

• You must be connected to a recovery catalog.
• RMAN updates physical schema information in the recovery catalog only when the target database has the current control file mounted. If the target database has mounted a backup control file, a freshly created control file, or a control file that is less current than a control file that was used previously, then RMAN does not update physical schema information in the recovery catalog.

Keywords and Parameters

Syntax Element	Description
FROM CONTROLFILECOPY 'filename'	Specifies the name of the control file copy to use for resynchronization. Physical schema information is not updated when you use this option.

Examples

Resynchronizing the Recovery Catalog in ARCHIVELOG Mode: Example

This example performs a full resynchronization after archiving all unarchived redo logs:

SQL "ALTER SYSTEM ARCHIVE LOG ALL";
RESYNC CATALOG;

Resynchronizing the Recovery Catalog After a Structural Change: Example

This example adds a datafile to tablespace users and then resynchronizes the catalog:

#!/usr/bin/tcsh
# connect in nocatalog mode and add datafile
rman TARGET / NOCATALOG <<EOF
SQL "ALTER TABLESPACE users ADD DATAFILE ''?/oradata/trgt/users03.dbf'' 
     SIZE 1M AUTOEXTEND ON NEXT 10K MAXSIZE 10M";
EXIT
EOF
# connect in catalog mode and resynchronize
rman TARGET / CATAOG rman/rman@catdb <<EOF
RESYNC CATALOG;
EOF