Skip Headers
Oracle® Database Backup and Recovery Reference
11g Release 2 (11.2)

Part Number E10643-03
Go to Documentation Home
Home
Go to Book List
Book List
Go to Table of Contents
Contents
Go to Index
Index
Go to Master Index
Master Index
Go to Feedback page
Contact Us

Go to previous page
Previous
Go to next page
Next
View PDF

SET

Purpose

Use the SET command to control RMAN behavior within a job or session. Use CONFIGURE to configure options that persist across sessions.

Prerequisites

You can use the SET command either at the RMAN prompt or within a RUN block. When used at the RMAN prompt, changes made by SET persist until you exit the RMAN client (see setRmanOption). When used inside of a RUN block, changes made by SET persist until the end of the RUN block or the next SET command that changes the value of the same attribute (see setRunOption).

Syntax

set::=

Surrounding text describes set.gif.

(setRmanOption::=, setRunOption::=)

setRmanOption::=

Surrounding text describes setrmanoption.gif.

(deviceSpecifier::=, formatSpec::=)

setRunOption::=

Surrounding text describes setrunoption.gif.

(deviceSpecifier::=, formatSpec::=, datafileSpec::=, tempfileSpec::=, untilClause::=)

setRmanOrRunOption::=

Surrounding text describes setrmanorrunoption.gif.

(deviceSpecifier::=, formatSpec::=)

Semantics

setRmanOption

This subclause specifies SET options that are usable outside of a RUN block.

Syntax Element Description

COMPRESSION ALGORITHM
'algorithm_name'
Specifies the compression algorithm for backup sets. This command overrides the current CONFIGURE COMPRESSION ALGORITHM setting for the current RMAN session.

You can configure the basic compression level, which does not require the Advanced Compression Option, by specifying BASIC for the algorithm_name.

If you have enabled the Oracle Database 11g Release 2 Advanced Compression Option, you can choose from the following compression levels:

  • HIGH - Best suited for backups over slower networks where the limiting factor is network speed

  • MEDIUM - Recommended for most environments. Good combination of compression ratios and speed

  • LOW - Least impact on backup throughput and suited for environments where CPU resources are the limiting factor.

Note: The compression ratio generally increases from LOW to HIGH, with a trade-off of potentially consuming more CPU resources.

Since the performance of the various compression levels depends on the nature of the data in the database, network configuration, system resources and the type of computer system and its capabilities, Oracle cannot document universally applicable performance statistics. The decision as to which level is best must factor in on how balanced your system is regarding bandwidth into the CPU as well as the actual speed of the CPU. It is highly recommended that you run tests with the different compression levels on the data in your environment. Choosing a compression level based on your environment, network traffic characteristics (workload) and dataset is the only way to ensure that the backup set compression level can satisfy your organization's performance requirements and any applicable service level agreements.

Note: V$RMAN_COMPRESSION_ALGORITHM describes supported algorithms.

See Also: Oracle Database Reference entry for $RMAN_COMPRESSION_ALGORITHM.


OPTIMIZE FOR LOAD
{TRUE|FALSE}
Specifies whether Oracle performs pre-compression block processing when compressed backups have been requested. TRUE is the default and FALSE enables pre-compression processing. The default behavior is not to perform pre-compression block processing. Such processing can consume extra CPU resources, and is not needed for blocks that contain all originally loaded data, and have never been the subject of single-row inserts and deletes. Specifying FALSE uses additional CPU resources to perform pre-compression block processing which consists of internal block cleanups and defragmentation that can result in improved levels of binary compression.

See Also: Oracle Database Backup and Recovery User's Guide to learn more about this option.


AS OF RELEASE
'version number'
Specifies the release version. The version number uses the release number format and may use as many as 5 numbers to fully qualify the release. For example, 10.2.0.3.0 and 11.2 are acceptable values. This option ensures compression algorithm stability across future releases.

DECRYPTION
IDENTIFIED BY password
Specifies one or more decryption passwords to be used when reading dual-mode or password-encrypted backups.

Password-encrypted backups require the correct password to be entered before they can be restored. When RMAN reads an encrypted backup piece, it tries each password in the list until it finds the correct one to decrypt this backup piece. RMAN signals an error if none of the specified keys work.

Note: If restoring from a group of backups created with different passwords, then specify all of the required passwords on the SET DECRYPTION command. RMAN will automatically use the correct password with each backup set.

See Also: "Encryption of Backup Sets"

ECHO {OFF | ON} Controls whether RMAN commands appear in the message log. When reading commands from a command file, RMAN automatically echoes them to the message log. When reading commands from standard input, by default RMAN does not echo these commands to the message log. To force RMAN to echo the commands, run the SET ECHO ON command before running your command file. Run SET ECHO OFF to disable echoing to the command log.

The command is useful when stdin and stdout have been redirected. For example, in UNIX you can redirect RMAN's input and output in this manner:

% rman TARGET / < in_file > out_file

By including SET ECHO ON in the in_file, you enable the commands contained in in_file to be visible in out_file.

ENCRYPTION Specifies encryption-related options that apply to BACKUP commands that create backup sets for the duration of the RMAN session.

See Also: "Encryption of Backup Sets"


   ALGORITHM
   'algorithm_name'
Specifies the algorithm used during this RMAN session. Overrides the configured default encryption algorithm specified by CONFIGURE ALGORITHM. Possible values are listed in V$RMAN_ENCRYPTION_ALGORITHMS.

   IDENTIFIED BY
   password [ONLY]
Specifies whether to employ a user-specified password in backup encryption according to the following rules:
  • Omit IDENTIFIED BY password clause to specify transparent-mode encrypted backups.

  • Use IDENTIFIED BY password ONLY to specify password-mode encrypted backups.

  • Use IDENTIFIED BY password without ONLY to specify dual-mode encrypted backups.

Create a password that is secure. See Oracle Database Security Guide for more information.

Note that if the password is not surrounded by quotes, then it is translated internally into upper case. Thus, the following clauses are all synonyms for IDENTIFIED BY "SOMEPWD":

  • IDENTIFIED BY somepwd

  • IDENTIFIED BY Somepwd

  • IDENTIFIED BY sOmEpWd

Caution: Wallet-based encryption is more secure than password-based encryption because no passwords are involved. You should use password-based encryption only when absolutely necessary because your backups need to be transportable.

See Also: "Encryption of Backup Sets" for details on the different encryption modes

   {OFF | ON} Specifies whether to encrypt backup sets. If ON, then the default is to encrypt backup sets. If OFF, then the default is not to encrypt backup sets.

This option overrides settings made with the CONFIGURE ENCRYPTION FOR command. If no datafiles are configured for encryption, then you must explicitly use ON to encrypt required datafiles.

If FOR ALL TABLESPACES is not specified, then this setting controls encryption of backups for tablespaces where CONFIGURE ENCRYPTION FOR TABLESPACE tablespace_name has not been used to control encryption behavior.

   FOR ALL TABLESPACES Controls encryption for all tablespaces, overriding any CONFIGURE ENCRYPTION FOR TABLESPACE tablespace_name setting.

setRunOption

This subclause specifies SET options that are usable within a RUN block.

Syntax Element Description

ARCHIVELOG DESTINATION
TO 'log_archive_dest'
Overrides the LOG_ARCHIVE_DEST_1 initialization parameter in the target database when forming names for restored archived redo log files during subsequent RESTORE and RECOVER commands. RMAN restores the logs to the destination specified in 'log_archive_dest'.

You can use this command to stage archived redo log files to different locations while restoring a database. RMAN knows where to find the newly restored archived redo log files; it does not require them to be in the destination specified by LOG_ARCHIVE_DEST_1. For example, if you specify a different destination from the one in the parameter file and restore archived log backups, subsequent restore and recovery operations detect this new location.

Use this parameter to restore archived redo log files that are not already on disk. RMAN always looks for logs on disk first before restoring them from backups.

BACKUP COPIES integer Specifies the number of copies of each backup piece that the channels should create: 1, 2, 3, or 4 (see Example 3-42).

RMAN can duplex backups to either disk or tape but cannot duplex backups to tape and disk simultaneously. When backing up to tape, ensure that the number of copies does not exceed the number of available tape devices. Also, if BACKUP COPIES is greater than 1, then the BACKUP_TAPE_IO_SLAVES initialization parameter must be enabled on the target database.

The SET BACKUP COPIES command affects all BACKUP commands in the RUN block issued after SET BACKUP COPIES (but not before) and is in effect until explicitly disabled or changed. The SET BACKUP COPIES command affects only BACKUP commands, but does not apply to the BACKUP AS COPY command.

The SET BACKUP COPIES command affects all channels allocated in the session. The order of precedence is as follows, with settings higher on the list overriding settings lower on the list:

  1. BACKUP COPIES

  2. SET BACKUP COPIES

  3. CONFIGURE ... BACKUP COPIES

The names of the backup pieces are dependent on the FORMAT clause in the BACKUP command. You can specify up to four FORMAT strings. RMAN uses the second, third, and fourth values only when BACKUP COPIES, SET BACKUP COPIES, or CONFIGURE ... BACKUP COPIES is in effect. When choosing which format to use for each backup piece, RMAN uses the first format value for copy 1, the second format value for copy 2, and so on. If the number of format values exceeds the number of copies, then the extra formats are not used. If the number of format values is less than the number of copies, RMAN reuses the format values, starting with the first one.

Note: BACKUP COPIES option is not valid when files are created in fast recovery area. Backups to the fast recovery area cannot be duplexed.

Note: Control file autobackups on disk are a special case and are never duplexed: RMAN always writes one and only copy.


MAXCORRUPT
FOR DATAFILE datafileSpec
TO integer
Sets a limit on the number of previously undetected block corruptions that the database will permit in a specified datafile or group of datafiles. The default limit is zero, meaning that RMAN tolerates no corrupt blocks.

The SET MAXCORRUPT command specifies the total number of physical and logical corruptions permitted in a datafile during a backup job. If the sum of physical and logical corruptions detected for a datafile is no more than its MAXCORRUPT setting, then the BACKUP command completes. If more than MAXCORRUPT corrupt blocks exist, then RMAN terminates without creating output files.

Whether or not the MAXCORRUPT limit is exceeded, RMAN populates the V$DATABASE_BLOCK_CORRUPTION view with any corrupt block ranges that it finds. However, a backup or restore job is terminated after MAXCORRUPT+1 corrupt blocks are found, so in this case RMAN only records MAXCORRUPT+1 corruptions. Any block corruptions beyond the point at which the backup job terminated are not recorded.

Note: If you specify CHECK LOGICAL, then the MAXCORRUPT limit applies to the sum of logical and physical corruptions detected. Otherwise, MAXCORRUPT only applies to the number of physical block corruptions.

See Also: datafileSpec


NEWNAME FOR
DATABASE
Sets new default names for all datafiles and tempfiles in the specified database that have not been named with the SET NEWNAME FOR TABLESPACE, SET NEWNAME FOR TEMPFILE or SET NEWNAME FOR DATAFILE command.

This command enables you to change the names for multiple files in the database and provides a quick alternative to naming each file individually (see Example 2-76). This command does not set names for tempfiles.

When issuing SET NEWNAME FOR DATABASE, you must specify at least one of the first three of the following substitution variables to avoid name collisions: %b, %f, and %U. See the semantic entry for TO 'filename' for descriptions of the possible substitution variables.

The new names are used for all subsequent DUPLICATE, RESTORE, SWITCH commands that affect the files in the database and when using the RMAN TSPITR utility. If you do not issue this command before the restore operation, then RMAN restores the files to their default locations.

You do not have to issue the SET NEWNAME commands in any particular order. For example, assume that you run the following series of commands:

SET NEWNAME FOR DATABASE TO '/oradata1/%b';
SET NEWNAME FOR TABLESPACE users TO '/oradata2/%U';
SET NEWNAME FOR DATAFILE 1 TO '+data';

The preceding series of commands is equivalent to the following differently ordered series of commands:

SET NEWNAME FOR DATAFILE 1 TO '+data;
SET NEWNAME FOR DATABASE TO '/oradata1/%b';
SET NEWNAME FOR TABLESPACE users TO '/oradata2/%U';

Note: The SET NEWNAME command supports ASM disk groups.

See Also: formatSpec to learn about substitution variables that are valid in SET NEWNAME FOR DATABASE


NEWNAME FOR
DATAFILE datafileSpec
Sets the default name for the specified datafile.

This command enables you to specify the names of each datafile individually (see Example 2-77). The new names are used for all subsequent DUPLICATE, RESTORE, SWITCH commands that affect the files in the database and when using the RMAN TSPITR utility.

If you run SET NEWNAME FOR DATAFILE and then restore a datafile to a new location, then you can run SWITCH to rename the file in the control file to the NEWNAME. If you do not run SWITCH, then RMAN records the restored file as a datafile copy in the RMAN repository.

Note: The SET NEWNAME command supports ASM disk groups.

See Also: datafileSpec


NEWNAME FOR TABLESPACE
tablespace_name
Sets new default names for all the files in the specified tablespace that have not been named with the SET NEWNAME FOR DATAFILE command.

This command allows you to change the names for multiple files in the duplicate tablespace and provides an alternative to naming each file of the tablespace individually (see Example 2-77).

When issuing SET NEWNAME FOR TABLESPACE, you must specify at least one of the first three of the following substitution variables to avoid name collisions: %b, %f, and %U. See the semantic entry for TO 'filename' for descriptions of the possible substitution variables.

The new names are used for all subsequent DUPLICATE, RESTORE or SWITCH commands that affect the files in the tablespace. If you do not issue this command before the restore operation, then RMAN restores the files to their default locations.

Note: The SET NEWNAME command supports ASM disk groups.

See Also: formatSpec to learn about substitution variables that are valid in SET NEWNAME FOR DATABASE


NEWNAME FOR
TEMPFILE tempfileSpec
Sets the new tempfile name for a subsequent SWITCH command that renames the specified tempfile to the specified name.

Note: The SET NEWNAME command supports ASM disk groups.

See Also: tempfileSpec

   TO 'filename' Specifies a user-defined filename or ASM disk group for the restored datafile or tempfile.

When issuing SET NEWNAME FOR DATABASE or SET NEWNAME FOR TABLESPACE, you must specify substitution variables within filename to avoid name collisions. Specify at least one of the first three of the following substitution variables (the %I and %N variables are optional):

  • %b

    Specifies the filename without the fully qualified directory path. For example, the datafile name /oradata/prod/financial.dbf is transformed to financial.dbf. This variable enables you to preserve the names of the datafiles while you move them to different directory. During backup, it can be used for the creation of image copies. The variable cannot be used for OMF datafiles or backup sets.

  • %f

    Specifies the absolute file number of the datafile for which the new name is generated. For example, if datafile 2 is duplicated, then %f generates the value 2.

  • %U

    Specifies a system-generated unique filename. The name is in the following format: data-D-%d_id-%I_TS-%N_FNO-%f. The %d variable specifies the database name. For example, a possible name might be data-D-prod_id-22398754_TS-users_FNO-7.

  • %I

    Specifies the DBID.

  • %N

    Specifies the tablespace name.

Note: Use of other substitution variables defined in formatSpec is undefined: some yield an error, while others result in zero values and are not supported.

If you set the NEWNAME to an ASM disk group for a datafile and run RESTORE, then RMAN restores the file to the disk group. If you specify a filename for a tempfile, then this will the new name of the tempfile after the database is recovered and opened.

   TO NEW Creates an Oracle-managed file in the directory specified by the DB_CREATE_FILE_DEST initialization parameter.

For example, SET NEWNAME FOR TABLESPACE users TO NEW sets OMF names for the datafiles of the users tablespace to be created in the DB_CREATE_FILE_DEST location (see Example 2-78).

If the original file is an Oracle-managed file or is on an ASM disk group, then RMAN attempts to delete the original file. If you specify TO NEW for a tempfile, then RMAN creates the tempfile in DB_CREATE_FILE_DEST when the database is opened.

See Also: Oracle Database Administrator's Guide for information about Oracle-managed files


TO RESTORE POINT
restore_point_name
Specifies a restore point for a subsequent RESTORE or RECOVER command, with the SCN at which the restore point was created as the upper, inclusive limit. Because the limit is inclusive, RMAN selects only files that can be used to restore or recover up to and including the SCN corresponding to the restore point.

Note: You can only use SET TO RESTORE POINT when the database is mounted, because the defined restore points are recorded in the control file. For example, you cannot use SET TO RESTORE POINT to specify the target SCN for a RESTORE CONTROLFILE operation.

untilClause Specifies an end time, SCN, or log sequence number for a subsequent RESTORE or RECOVER command.

See Also: untilClause


setRmanOrRunOption

This subclause specifies SET options that are usable inside or outside of a RUN block.

Syntax Element Description

AUXILIARY INSTANCE PARAMETER
FILE TO 'filename'
Specifies the path to the parameter file to use in starting the instance. You can use this parameter when customizing TSPITR with an automatic auxiliary instance or when cloning RMAN tablespaces with RMAN.

Note: The filename is on the host running the RMAN client.

See Also: Oracle Database Reference for more on V$SESSION.CLIENT_INFO

COMMAND ID TO 'string' Enters the specified string into the V$SESSION.CLIENT_INFO column of all channels. Use this information to determine which database server sessions correspond to which RMAN channels. The SET COMMAND ID command applies only to channels that are already allocated.

The V$SESSION.CLIENT_INFO column contains information for each RMAN server session. The data appears in one of the following formats:

  • id=string

  • id=string, ch=channel_id

The first form appears in the RMAN target database connection. The second form appears in all allocated channels. When the current job is complete, the V$SESSION.CLIENT_INFO column will be cleared.

See Also: Oracle Database Reference for more on V$SESSION.CLIENT_INFO


CONTROLFILE AUTOBACKUP
FORMAT FOR DEVICE TYPE
deviceSpecifier
TO formatSpec
Overrides the default filename format for the control file autobackup on the specified device type. You can use this command either in RUN or at the RMAN prompt. The order of precedence is as follows:
  1. SET CONTROLFILE AUTOBACKUP executed within a RUN block

  2. SET CONTROLFILE AUTOBACKUP executed at the RMAN prompt

  3. CONFIGURE CONTROLFILE AUTOBACKUP FORMAT

The %F substitution variable is required to be in the new formatSpec. No other substitution variable is valid in a control file autobackup formatSpec.

See Also: formatSpec for the semantics of the %F substitution variable

DATABASE 'database_name' Specifies the name of the database that you want to copy (source database) when duplicating without a connection to the target database. Alternatively, you can use the DATABASE clause of the DUPLICATE command to specify the source database when you have chosen not to connect to the target database for the duplicate.
DBID integer Specifies the DBID, which is a unique 32-bit identification number computed when the database is created.

RMAN displays the DBID upon connection to the target database. You can obtain the DBID by querying the V$DATABASE view or the RC_DATABASE and RC_DATABASE_INCARNATION recovery catalog views.

You should only run the SET DBID command in the following specialized circumstances:

  • You are not connected to a recovery catalog and want to restore the control file (see Example 3-43). The same restriction applies when you use the Data Recovery Advisor to restore a control file autobackup. CONFIGURE can locate an autobackup and restore it only if SET DBID is issued before ADVISE FAILURE.

  • You want to restore the server parameter file (see Example 3-44).

  • You are connected to the recovery catalog but not the target database and use the FOR DB_UNIQUE_NAME option on the CONFIGURE, LIST, REPORT, SHOW, or UNREGISTER commands.

  • You are connected to the recovery catalog and want to restore the controlfile but the target database is not mounted and the database name is not unique in the recovery catalog.

  • You are performing a DUPLICATE without a target connection but are not using the DBID subclause in the DUPLICATE command and the database name specified in SET DATABASE or DATABASE clause is not unique in the recovery catalog.

INCARNATION primaryKey Allows you to specify an orphan incarnation when duplicating without a target connection under the following conditions:
  • You have not specified INCARNATION within the DATABASE clause of the DUPLICATE command.

  • You want to duplicate to an incarnation not in the current incarnation path (orphan incarnation).


Examples

Example 3-41 Setting the Command ID

This example sets the command ID to rman, backs up the database, and then archives the online redo logs. You can use the command ID to query V$SESSION with WHERE LIKE '%rman%' for job status information.

RUN
{
  ALLOCATE CHANNEL d1 DEVICE TYPE DISK FORMAT '/disk1/%U';
  ALLOCATE CHANNEL d2 DEVICE TYPE DISK FORMAT '/disk2/%U';
  SET COMMAND ID TO 'rman';
  BACKUP INCREMENTAL LEVEL 0 DATABASE;
  SQL 'ALTER SYSTEM ARCHIVE LOG CURRENT';
}

Example 3-42 Duplexing a Backup Set

Assume that the current duplexing configuration is as follows:

CONFIGURE ARCHIVELOG COPIES FOR DEVICE TYPE sbt TO 3;
CONFIGURE DATAFILE COPIES FOR DEVICE TYPE sbt TO 3;

One of the tape drives goes bad, leaving only two available. The guideline for tape backups is that the number of devices should equal the number of copies multiplied by the number of channels. The following example overrides the persistent duplexing configuration with SET BACKUP COPIES and writes two copies of a database backup to the two functioning tape drives:


RUN
{
  ALLOCATE CHANNEL dev1 DEVICE TYPE sbt
    PARMS 'ENV=(OB_DEVICE_1=stape1,OB_DEVICE_2=stape2)';
  SET BACKUP COPIES 2;
  BACKUP DATABASE PLUS ARCHIVELOG;
}

Example 3-43 Setting the Control File Autobackup Format During a Restore

Assume that the disk containing the control file fails. You edit the CONTROL_FILES parameter in the initialization parameter file to point to a new location.

In this example, you do not have access to a recovery catalog. The example starts the instance, sets the DBID, and then restores a control file autobackup. After the database is mounted, you can recover the database.

CONNECT TARGET /
STARTUP FORCE NOMOUNT
SET DBID 28014364;
RUN
{
  SET CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '/disk2/cf_%F.bak';
  RESTORE CONTROLFILE FROM AUTOBACKUP MAXSEQ 100;
}
ALTER DATABASE MOUNT;
RECOVER DATABASE;
ALTER DATABASE OPEN RESETLOGS;

Example 3-44 Restoring the Server Parameter File

Assume that the database is shut down while maintenance is being performed on the database host. During this time, the server parameter file is accidentally deleted. You start the RMAN client, CONNECT as TARGET to the database, and connect to the recovery catalog. The following example restores a server parameter file from an autobackup on tape and then restarts the instance.

SET DBID 3257174182;  # set dbid so RMAN can identify the database
STARTUP FORCE NOMOUNT # RMAN starts database with a dummy server parameter file
RUN
{
  ALLOCATE CHANNEL t1 DEVICE TYPE sbt;
  RESTORE SPFILE FROM AUTOBACKUP;
}
STARTUP FORCE; # RMAN restarts database with restored server parameter file

Example 3-45 Setting NEWNAME and Duplicating Without a Connection to Target Database

Assume that you want to duplicate a database without a connection to the target database and that you want to duplicate to an incarnation that is not in the current incarnation path (451). The following example uses the various SET NEWNAME commands, sets the DBID and duplicates the database to NEWDB:

SET DATABASE PROD
SET DBID 22398754
SET INCARNATION 451
RUN
{
SET NEWNAME FOR TABLESPACE system TO '/test/oradata/system/%d_%f';
SET NEWNAME FOR TABLESPACE users to '/test/oradata/users/%b';
SET NEWNAME FOR DATAFILE 35 to '/test/oradata/special/%N_%b_%f';
SET NEWNAME FOR DATAFILE 50 to '/test/oradata/special/%N_%b_%f';
SET NEWNAME FOR DATABASE to NEW;
DUPLICATE DATABASE TO newdb
SKIP READONLY
LOGFILE
GROUP 1 ('/test/onlinelogs/redo01_1.f',
'?/test/onlinelogs/redo01_2.f') SIZE 4M,
GROUP 2 ('?/test/onlinelongs/redo02_1.f',
'?/test/onlinelongs/redo02_2.f') SIZE 4M,
GROUP 3 ('?/test/onlinelogs/redo03_1.f',
'?/test/onlinelogs/redo03_2.f') SIZE 4M REUSE;
}

Example 3-46 Setting a Compression Level for a Backup

This example assumes that you have a license for Advanced Compression Option (ACO) of the database.

To use the LOW compression algorithm for a backup of tablespace users that has high volatility:

SET COMPRESSION ALGORITHM 'LOW' OPTIMIZE FOR LOAD FALSE;
BACKUP AS COMPRESSED BACKUPSET TABLESPACE USERS;