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Oracle® Database Backup and Recovery User's Guide
12c Release 1 (12.1)

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4 Starting and Interacting with the RMAN Client

This chapter explains how to start the RMAN command-line interface and make database connections. This chapter contains the following topics:

Starting and Exiting RMAN

The RMAN executable is automatically installed with the database and is typically located in the same directory as the other database executables. For example, the RMAN client on Linux is located in $ORACLE_HOME/bin. You have the following basic options for starting RMAN:

To quit RMAN and terminate the program, enter EXIT or QUIT at the RMAN prompt:

RMAN> EXIT

See Also:

Oracle Database Backup and Recovery Reference for RMAN command-line syntax

Making Database Connections with RMAN

This section explains how to connect the RMAN client to Oracle Database. It contains the following topics:

About RMAN Database Connection Types

To perform useful work, the RMAN client must connect to a database. Table 4-1 describes the types of database connections that you can make with RMAN.

Table 4-1 Overview of RMAN Database Connections

Type of Database Connection Keyword Description

target database

TARGET

A database to be backed up or recovered by RMAN

recovery catalog database

CATALOG

A database that provides an optional backup store for the RMAN repository in addition to the control file.

auxiliary instance or auxiliary database

AUXILIARY

A physical standby database, or a database instance created for performing a specific task such as creating a duplicate database, transporting tablespaces, or performing tablespace point-in-time recovery (TSPITR).

For many tasks that use an auxiliary database, RMAN creates an automatic auxiliary instance for use during the task, connects to it, performs the task, and then destroys it when the task is completed. You do not give any explicit command to connect to automatic auxiliary instances.


Authentication for RMAN Database Connections

Users connecting with RMAN to a target or auxiliary database require either the SYSDBA or SYSBACKUP system privilege. These privileges are not required when connecting to the recovery catalog. You must grant the RECOVERY_CATALOG_OWNER role to the catalog schema owner. Users can also connect to the recovery catalog using the VPC credentials that have been created by the recovery catalog owner.

The same authentication options that are available with SQL*Plus are available with RMAN. The most common ways to authenticate with the target and auxiliary databases are:

  • Operating system authentication

  • Password file authentication

Neither of these methods requires the database to be open. Operating system authentication is used only to connect locally. Password file authentication can be used to connect locally or remotely.

See Also:

Authentication Using the Operating System

The following are the prerequisites for connecting to a database using operating system authentication (OS authentication):

  • You must set the ORACLE_SID environment variable, specifying the system identifier (SID) for the database.

    For example, to set the SID to prod in some UNIX shells, you enter:

    % ORACLE_SID=prod; export ORACLE_SID
    
  • You must be a member of the OSDBA operating system group to connect with the SYSDBA privilege or the OSBACKUPDBA operating system group to connect with the SYSBACKUP privilege.

    On UNIX and Linux, the OSDBA group is typically named dba, and the OSBACKUPDBA group is typically named backupdba. These names are assigned during database installation.

The following examples illustrate how to connect to a target database with operating system authentication.

Example 4-1 OS Authentication with the SYSDBA Privilege - Explicit

% rman target '"/ as sysdba"'

Example 4-2 OS Authentication with the SYSBACKUP Privilege - Explicit

% rman target '"/ as sysbackup"'

Example 4-3 OS Authentication with the SYSDBA Privilege - Implicit

rman target /

If neither AS SYSBACKUP nor AS SYSDBA is specified in the connection string, then the default used is AS SYSDBA.

See Also:

Oracle Database Administrator's Guide for a discussion of operating system groups

Authentication Using a Password File

If a database uses a password file to authenticate administrative users, then RMAN can connect using a password. Use a password file for either local or remote access.

The database must use a password file for you to connect remotely using a net service name.

Caution:

Good security practice requires that passwords not be entered in plain text on the command line. Enter passwords in RMAN only when requested by an RMAN prompt. See Oracle Database Security Guide to learn about password protection.

The database creates an entry in the password file when you grant the SYSDBA or SYSBACKUP privilege to a user. You can then connect to the target or auxiliary database as this user even if the database is not open.

To support connecting through the password file with the SYSBACKUP privilege, the password file must be created in or upgraded to the format for Oracle Database 12c Release 1 (12.1) or later.

Example 4-4 Password File Authentication as SYSDBA - Explicit

In this example, the sdba user has been granted the SYSDBA privilege:

% rman target '"sdba@prod1 as sysdba"' 

target database Password: password
connected to target database: PROD1 (DBID=39525561)

Example 4-5 Password File Authentication as SYSBACKUP - Explicit

In this example, the sbu user is granted the SYSBACKUP privilege in the target database:

% rman target '"sbu@prod1 as sysbackup"' 

target database Password: password
connected to target database: PROD1 (DBID=39525561)

Example 4-6 Password File Authentication as SYSDBA - Implicit

% rman target sbu@prod1

target database Password: password
connected to target database: PROD1 (DBID=39525561)

If neither AS SYSBACKUP nor AS SYSDBA is specified in the connection string, then the default used is AS SYSDBA. In this case, no enclosing quotes are required.

See Also:

Oracle Database Administrator's Guide to learn about password files

Making Database Connections from the RMAN Prompt

If you start RMAN without a connect string on the operating system command line, then you must issue a CONNECT TARGET command at the RMAN prompt to connect to a target database.

To make a database connection from the RMAN prompt:

  1. On the operating system command line, start the RMAN client without making a database connection.

    % rman
    RMAN>
    
  2. At the RMAN prompt, enter one or more CONNECT commands.

Example 4-7 Connecting With OS Authentication - Implicit

RMAN> connect target /

Because no system privilege is specified, AS SYSDBA is assumed.

Example 4-8 Connecting with OS Authentication - Explicit

RMAN> connect target "/ as sysdba"

When including a system privilege, the enclosing quotation marks (single or double) are required.

Example 4-9 Connecting with Password File Authentication

RMAN> connect target "sbu@prod AS SYSBACKUP"

target database Password: password
connected to target database: PROD (DBID=39525561)

Example 4-10 Connecting to Target and a Recovery Catalog

In this example, the target connection uses operating system authentication, and the recovery catalog database connection uses a net service name and password file authentication. The recovery catalog owner is user rco. RMAN prompts for the password of the recovery catalog user.

RMAN> connect target /
RMAN> connect catalog rco@catdb

recovery catalog database Password: password
connected to recovery catalog database

See Also:

Oracle Database Backup and Recovery Reference to learn about the CONNECT command

Making RMAN Database Connections from the Operating System Command Line

To connect to a target database from the operating system command line, enter the rman command followed by the connection information. You can begin executing commands after the RMAN prompt is displayed.

Example 4-11 illustrates a connection to a target database that uses operating system authentication. The NOCATALOG option indicates that a recovery catalog is not used in the session.

Example 4-11 Connecting to a Target Database from the System Prompt

% rman TARGET / NOCATALOG

connected to target database: PROD (DBID=39525561)
using target database control file instead of recovery catalog
 
RMAN>

Example 4-12 illustrates a connection to a target database that uses a net service name and password file authentication. RMAN prompts for the password.

Example 4-12 Connecting to a Target Database from the System Prompt by Using Net Service Names

% rman TARGET sbu@prod NOCATALOG

target database Password: password
connected to target database: PROD (DBID=39525561)

RMAN>

Use the CATALOG keyword to connect to a recovery catalog. Example 4-13 illustrates a connection that uses Oracle Net authentication for the target and recovery catalog databases. In both cases RMAN prompts for a password.

Example 4-13 Connecting to Target and a Recovery Catalog from the System Prompt

% rman TARGET sbu@prod CATALOG rco@catdb

target database Password: password
connected to target database: PROD (DBID=39525561)
recovery catalog database Password: password
connected to recovery catalog database

RMAN>

You can also start RMAN without specifying NOCATALOG or CATALOG. If you do not specify NOCATALOG on the command line, and if you do not specify CONNECT CATALOG after RMAN has started, then RMAN defaults to NOCATALOG mode the first time that you run a command that requires the use of the RMAN repository.

Note:

After you have executed a command that uses the RMAN repository in NOCATALOG mode, you must exit and restart RMAN to be able to connect to a recovery catalog.

If you connect to the target database on the operating system command line, then you can begin executing commands after the RMAN prompt is displayed.

Connecting RMAN to an Auxiliary Database

To use the DUPLICATE command, you must connect to an auxiliary instance. To perform RMAN tablespace point-in-time recovery (TSPITR), you may also need to connect to an auxiliary instance.

Note:

When you use the DUPLICATE ... FROM ACTIVE DATABASE command, a net service name is required. See "Step 7: Creating an Initialization Parameter File and Starting the Auxiliary Instance" for more details.

The form of an auxiliary connection is identical to a target database connection, except that you use the AUXILIARY keyword instead of the TARGET keyword.

Example 4-14 illustrates a connection to a target database using operating system authentication, and the auxiliary database connection uses a net service name and password file authentication.

Example 4-14 Connecting to Target and Auxiliary Databases from the RMAN Prompt

% rman
RMAN> CONNECT TARGET /
RMAN> CONNECT AUXILIARY sbu@aux

auxiliary database Password: password
connected to auxiliary database: AUX (DBID=30472568)

Example 4-15 illustrates a connection to a target database and an auxiliary database from the system prompt. The target connection uses operating system authentication and the auxiliary connection uses a net service name and password file authentication.

Example 4-15 Connecting to Target and Auxiliary Databases from the System Prompt

% rman target / auxiliary sbu@aux

auxiliary database Password: password
connected to auxiliary database: AUX (DBID=30472568)

See Also:

Making RMAN Connections to a CDB

This section describes how to connect the RMAN client to multitenant container databases (CDBs) and pluggable databases (PDBs). It contains the following topics:

About Backup and Recovery of CDBs

You can perform RMAN operations on a whole CDB, the root only, or one or more PDBs. You make RMAN connections to CDBs according to the following rules:

  • To perform operations on the whole CDB (for example, to back up the whole CDB) you connect as target to the root.

  • To perform operations on the root only (for example, to back up the root) you connect as target to the root.

  • To perform operations on a single PDB, you can connect as target either to the root or directly to the PDB.

    • If you connect to the root, you must use the PLUGGABLE DATABASE syntax in your RMAN commands. For example, to back up a PDB, you use the BACKUP PLUGGABLE DATABASE command.

    • If instead you connect directly to a PDB, you can use the same commands that you would use when connecting to a non-CDB. For example, to back up a PDB, you would use the BACKUP DATABASE command.

  • To perform operations on two or more PDBs with a single command, you connect as target to the root.

    For example, to back up both the sales and hr PDBs, you connect to the root and submit the following command:

    BACKUP PLUGGABLE DATABASE sales, hr;
    

Note:

If you connect as target to a CDB with operating system authentication, you are connected to the root.

Restrictions When Connected to a PDB

The following operations are not available when you connect as target directly to a PDB:

  • Back up archived logs

  • Delete archived logs

  • Delete archived log backups

  • Restore archived logs (RMAN does restore archived logs when required during media recovery.)

  • Point-in-time recovery (PITR)

  • TSPITR

  • Table recovery

  • Duplicate database

  • Flashback operations

  • Running Data Recovery Advisor

  • Report/delete obsolete

  • Register database

  • Import catalog

  • Reset database

  • Configuring the RMAN environment (using the CONFIGURE command)

Note:

When you connect as TARGET to a PDB, you cannot connect to a recovery catalog.

Connecting as Target to the Root

There are several ways to connect as target to the root. The three most common ways are as follows:

  • Connecting locally as a common user, as shown in Example 4-16

  • Connecting with operating system authentication, as shown in Example 4-17

  • Connecting as a common user through Oracle Net Services, using a net service name, as shown in Example 4-18

In all cases, you must connect as a user with the SYSDBA or SYSBACKUP privilege.

Example 4-16 connects locally to the root using the SYS user, which is a common user. The connection is established using the SYSDBA privilege.

Example 4-16 Connecting Locally to the Root

rman target sys

target database Password: password
connected to target database: CDB (DBID=659628168)

Example 4-17 connects locally to the root using operating system authentication. The connection is established as the SYS user with SYSDBA privilege.

Example 4-17 Connecting to the Root with Operating System Authentication

rman target /
 
connected to target database: CDB (DBID=659628168)

Example 4-18 assumes that there is a sales net service name that resolves to a database service for the root, and that there is a common user named c##bkuser that has the SYSBACKUP privilege.

Example 4-18 Connecting to the Root with a Net Service Name

rman target c##bkuser@sales
 
target database Password: password
connected to target database: CDB (DBID=659628168)

Connecting as Target to a PDB

To connect as target to a PDB, you must:

  • Connect with a net service name that resolves to a database service for that PDB.

  • Connect as a local user or common user with the SYSDBA privilege.

Example 4-19 illustrates a connection to a PDB. It assumes the following

  • You want to perform RMAN operations on a PDB named hrpdb.

  • The net service name hrpdb resolves to a database service for the hrpdb PDB.

  • The local user hrbkup was created in the hrpdb PDB and granted the SYSDBA privilege.

Example 4-19 Connecting As Target to a PDB

rman target hrbkup@hrpdb
 
target database Password: password
connected to target database: CDB (DBID=659628168)

Making RMAN Database Connections Within Command Files

If you create an RMAN command file that uses a CONNECT command with database level credentials (user name and password), then anyone with read access to this file can learn the password. There is no secure way to incorporate a CONNECT string with a password into a command file.

If you create an RMAN command file that uses a CONNECT command, then RMAN does not echo the connect string when you run the command file with the @ command. This behavior prevents connect strings from appearing in any log files that contain RMAN output. For example, suppose that you create a command file listbkup.rman as follows:

cat > listbkup.rman << EOF
CONNECT TARGET /
LIST BACKUP;
EOF

You execute this script by running RMAN with the @ command line option as follows:

% rman @listbkup.rman

When the command file executes, RMAN replaces the connection string with an asterisk, as shown in the following output:

RMAN> CONNECT TARGET *
2> LIST BACKUP;
3>
connected to target database: RDBMS (DBID=771530996)

using target database control file instead of recovery catalog

List of Backup Sets
===================
. . .

Diagnosing RMAN Connection Problems

When you are diagnosing errors that RMAN encounters in connecting to the target, catalog and auxiliary databases, consider using SQL*Plus to connect to the databases directly. This action can reveal underlying problems with the connection information or the databases.

Diagnosing Target and Auxiliary Database Connection Problems

RMAN connects to target and auxiliary databases using the SYSDBA or SYSBACKUP privilege. Thus, when you use SQL*Plus to diagnose connection problems to the target or auxiliary databases, request a SYSDBA or SYSBACKUP connection to reproduce RMAN behavior.

For example, suppose that the following RMAN command encountered connection errors:

RMAN> CONNECT TARGET /

You reproduce the preceding connection attempt with the SQL*Plus command as follows:

SQL> CONNECT / AS SYSBACKUP

Diagnosing Recovery Catalog Connection Problems

When RMAN connects to the recovery catalog database, it does not use the SYSDBA or SYSBACKUP privilege. When you use SQL*Plus to diagnose connection problems to the recovery catalog database, you must enter the database connect string exactly as it was entered into RMAN. Do not specify AS SYSBACKUP or AS SYSDBA.

Specifying the Location of RMAN Output

By default, RMAN writes command output to standard output. To redirect output to a log file, enter the LOG parameter on the command line when you start RMAN, as in the following example:

% rman LOG /tmp/rman.log

In this case, RMAN displays command input but does not display the RMAN output. The easiest way to send RMAN output both to a log file and to standard output is to use the Linux tee command or its equivalent. For example, the following technique enables both input and output to be visible in the RMAN command-line interface:

% rman | tee rman.log
RMAN>

See Also:

Oracle Database Backup and Recovery Reference to learn about RMAN command-line options

Setting Globalization Support Environment Variables for RMAN

Before invoking RMAN, it may be useful to set the NLS_DATE_FORMAT and NLS_LANG environment variables. These variables determine the format used for the time parameters in RMAN commands such as RESTORE, RECOVER, and REPORT.

The following example shows typical language and date format settings:

NLS_LANG=american
NLS_DATE_FORMAT='Mon DD YYYY HH24:MI:SS'

If you are going to use RMAN to connect to an unmounted database and mount the database later while RMAN is still connected, then set the NLS_LANG environment variable so that it also specifies the character set used by the database.

A database that is not mounted assumes the default character set, which is US7ASCII. If your character set is different from the default, then RMAN returns errors after the database is mounted. For example, if the character set is WE8DEC, then to avoid errors, you can set the NLS_LANG variable as follows:

NLS_LANG=american_america.we8dec

For the environment variable NLS_DATE_FORMAT to be applied and override the defaults set for the server in the server initialization file, the environment variable NLS_LANG must also be set.

See Also:

Entering RMAN Commands

You can enter RMAN commands either directly from the RMAN prompt or read them in from a text file.

This section contains the following topics:

Entering RMAN Commands at the RMAN Prompt

When the RMAN client is ready for your commands, it displays the command prompt, as in this example:

RMAN> 

Enter commands for RMAN to execute. For example:

RMAN> CONNECT TARGET
RMAN> BACKUP DATABASE;

Most RMAN commands take several parameters and must end with a semicolon. Some commands, such as STARTUP, SHUTDOWN, and CONNECT, can be used with or without a semicolon.

When you enter a line of text that is not a complete command, RMAN prompts for continuation input with a line number. For example:

RMAN> BACKUP DATABASE
2> INCLUDE CURRENT 
3> CONTROLFILE
4> ;

Using Command Files with RMAN

For repetitive tasks, you can create a text file containing RMAN commands, and start the RMAN client with the @ argument, followed by a file name. For example, create a text file cmdfile1 in the current directory containing one line of text as shown here:

BACKUP DATABASE PLUS ARCHIVELOG;

You can run this command file from the command line as shown in this example, and the command contained in it is executed:

% rman TARGET / @cmdfile1

After the command completes, RMAN exits.

You can also use the @ command at the RMAN command prompt to execute the contents of a command file during an RMAN session. RMAN reads the file and executes the commands in it. For example:

RMAN> @cmdfile1

After the command file contents have been executed, RMAN displays the following message:

RMAN>  **end-of-file**

Unlike the case where a command file is executed from the operating system command line, RMAN does not exit.

See Also:

Oracle Database Backup and Recovery Reference for RMAN command-line syntax

Entering Comments in RMAN Command Files

The comment character in RMAN is a pound sign (#). All text from the pound sign to the end of the line is ignored. For example, the contents of the following command file back up the database and archived redo log files and include comments:

# Command file name: mybackup.rman
# The following command backs up the database
BACKUP DATABASE;
# The following command backs up the archived redo logs
BACKUP ARCHIVELOG ALL;

The following example shows how you can break a single RMAN command across multiple lines:

RMAN> BACKUP # this is a comment
2> SPFILE;

Using Substitution Variables in Command Files

When running a command file, you can specify one or more values in a USING clause for use in substitution variables in a command file. In this way, you can make your command files dynamic.

As in SQL*Plus, &1 indicates where to place the first value, &2 where to place the second value, and so on. The substitution variable syntax is &integer followed by an optional period, for example, &1.3. The optional period is part of the variable and replaced with the value, thus enabling the substitution text to be immediately followed by another integer. For example, if you pass the value mybackup to a command file containing the variable &1.3, then the result of the substitution is mybackup3.

The following procedure explains how to create and use a dynamic shell script that calls a command file containing substitution variables.

To create and use a dynamic shell script:

  1. Create an RMAN command file that uses substitution variables.

    The following example shows the contents of a command file named quarterly_backup.cmd, which is run every quarter. The script uses substitution variables for the name of the tape set, for a string in the FORMAT specification, and for the name of the restore point to be created.

    
    # quarterly_backup.cmd
    CONNECT TARGET /
    RUN
    {
      ALLOCATE CHANNEL c1
        DEVICE TYPE sbt
        PARMS 'ENV=(OB_MEDIA_FAMILY=&1)';
      BACKUP DATABASE 
        TAG &2 
        FORMAT '/disk2/bck/&1%U.bck'
        KEEP FOREVER 
        RESTORE POINT &3;
    }
    EXIT;
    
  2. Create a shell script that you can use to run the RMAN command file created in the previous step.

    The following example creates a shell script named runbackup.sh. The example creates shell variables for the format and restore point name and accepts the values for these variables as command-line arguments to the script.

    
    #!/bin/tcsh
    # name: runbackup.sh
    # usage: use the tag name and number of copies as arguments
    set media_family = $argv[1]
    set format = $argv[2]set restore_point = $argv[3]
    rman @'/disk1/scripts/quarterly_backup.cmd' USING $media_family $format $restore_point
    
  3. Execute the shell script created in the previous step, specifying the desired arguments on the command line.

    The following example runs the runbackup.sh shell script and passes it archival_backup as the media family name, bck0906 as the format string, and FY06Q3 as the restore point name.

    % runbackup.sh archival_backup bck0906 FY06Q3
    

Checking RMAN Syntax

You may want to test RMAN commands for syntactic correctness without executing them. Use the command-line argument CHECKSYNTAX to start the RMAN client in a mode in which it only parses the commands that you enter and returns an RMAN-00558 error for commands that are not legal RMAN syntax.

See Also:

Oracle Database Backup and Recovery Reference to learn about the CHECKSYNTAX command-line option

Checking RMAN Syntax at the Command Line

You can check the syntax of RMAN commands interactively without actually executing the commands.

To check RMAN syntax at the command line:

  1. Start RMAN with the CHECKSYNTAX parameter:

    % rman CHECKSYNTAX
    
  2. Enter the RMAN commands to be tested.

The following example shows a sample interactive session, with user-entered text in bold.


RMAN> run [ backup database; ]
 
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-00558: error encountered while parsing input commands
RMAN-01006: error signaled during parse 
 RMAN-02001: unrecognized punctuation symbol "["
 
RMAN> run { backup database; }

The command has no syntax errors

RMAN>

Checking RMAN Syntax in Command Files

To test commands in a command file, start RMAN with the CHECKSYNTAX parameter and use the @ command to name the command file to be passed.

To test commands in a command file:

  1. Use a text editor to create a command file.

    Assume that you create the /tmp/goodcmdfile with the following contents:

    # command file with legal syntax
    RESTORE DATABASE; 
    RECOVER DATABASE;
    

    Assume that you create another command file, /tmp/badcmdfile, with the following contents:

    # command file with bad syntax commands
    RESTORE DATABASE
    RECOVER DATABASE
    
  2. Run the command file from the RMAN prompt in the following format, where filename is the name of the command file:

    % rman CHECKSYNTAX @filename
    

The following example shows the output when you run /tmp/goodcmdfile with CHECKSYNTAX:


RMAN> # command file with legal syntax
2> restore database;
3> recover database;
4>
The cmdfile has no syntax errors
 
Recovery Manager complete.

In contrast, the following example shows the output when you run /tmp/badcmdfile with CHECKSYNTAX:


RMAN> #command file with syntax error
2> restore database
3> recover
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS===============
RMAN-00571: ===========================================================
RMAN-00558: error encountered while parsing input commands
RMAN-01005: syntax error: found "recover": expecting one of: "archivelog, 
      channel, check, controlfile, clone, database, datafile, device, 
      from, force, high, (, preview, ;, skip, spfile, standby, tablespace, 
      until, validate"
RMAN-01007: at line 3 column 1 file: /tmp/badcmdfile

As explained in "Using Substitution Variables in Command Files", you make your command files dynamic by including substitution variables. When you check the syntax of a command file that contains substitution variables, RMAN prompts you to enter values. Example 4-20 illustrates what happens if you enter invalid values when checking the syntax of a dynamic command file. The text in bold indicates text entered at the prompt.

Example 4-20 Checking the Syntax of a Command File with Bad Syntax

RMAN> CONNECT TARGET *
2> BACKUP TAG 
Enter value for 1: mybackup
abc COPIES 
Enter value for 2: mybackup
abc
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-00558: error encountered while parsing input commands
RMAN-01009: syntax error: found "identifier": expecting one of: "integer"
RMAN-01008: the bad identifier was: mybackup
RMAN-01007: at line 2 column 25 file: /tmp/whole_db.cmd

RMAN indicates a syntax error because the string mybackup is not a valid argument for COPIES.

Using the RMAN Pipe Interface

The RMAN pipe interface is an alternative method for issuing commands to RMAN and receiving the output from those commands. With this interface, RMAN obtains commands and sends output by using the DBMS_PIPE PL/SQL package instead of the operating system shell. Using this interface, it is possible to write a portable programmatic interface to RMAN.

The pipe interface is invoked by using the PIPE command-line parameter for the RMAN client. RMAN uses two private pipes: one for receiving commands and the other for sending output. The names of the pipes are derived from the value of the PIPE parameter. For example, you can invoke RMAN with the following command:

% rman PIPE abc TARGET /

RMAN opens the two pipes in the target database: ORA$RMAN_ABC_IN, which RMAN uses to receive user commands, and ORA$RMAN_ABC_OUT, which RMAN uses to send all output back to RMAN. All messages on both the input and output pipes are of type VARCHAR2.

RMAN does not permit the pipe interface to be used with public pipes, because they are a potential security problem. With a public pipe, any user who knows the name of the pipe can send commands to RMAN and intercept its output.

If the pipes are not initialized, then RMAN creates them as private pipes. If you want to put commands on the input pipe before starting RMAN, you must first create the pipe by calling DBMS_PIPE.CREATE_PIPE. Whenever a pipe is not explicitly created as a private pipe, the first access to the pipe automatically creates it as a public pipe, and RMAN returns an error if it is told to use a public pipe.

Note:

If multiple RMAN sessions can run against the target database, then you must use unique pipe names for each RMAN session. The DBMS_PIPE.UNIQUE_SESSION_NAME function is one method that you can use to generate unique pipe names.

Executing Multiple RMAN Commands in Succession Through a Pipe: Example

This scenario assumes that the application controlling RMAN wants to run multiple commands in succession. After each command is sent down the pipe and executed and the output returned, RMAN pauses and waits for the next command.

To execute RMAN commands through a pipe:

  1. Start RMAN by connecting to a target database (required) and specifying the PIPE option. For example, enter:

    % rman PIPE abc TARGET /
    

    You can also specify the TIMEOUT option, which forces RMAN to exit automatically if it does not receive any input from the input pipe in the specified number of seconds. For example, enter:

    % rman PIPE abc TARGET / TIMEOUT 60
    
  2. Connect to the target database and put the desired commands on the input pipe by using DBMS_PIPE.PACK_MESSAGE and DBMS_PIPE.SEND_MESSAGE. In pipe mode, RMAN issues message RMAN-00572 when it is ready to accept input instead of displaying the standard RMAN prompt.

  3. Read the RMAN output from the output pipe by using DBMS_PIPE.RECEIVE_MESSAGE and DBMS_PIPE.UNPACK_MESSAGE.

  4. Repeat Steps 2 and 3 to execute further commands with the same RMAN instance that was started in Step 1.

  5. If you used the TIMEOUT option when starting RMAN, then RMAN terminates automatically after not receiving any input for the specified length of time. To force RMAN to terminate immediately, send the EXIT command.

Executing RMAN Commands in a Single Job Through a Pipe: Example

This scenario assumes that the application controlling RMAN wants to run one or more commands as a single job. After running the commands that are on the pipe, RMAN exits.

To execute RMAN commands in a single job through a pipe:

  1. After connecting to the target database, create a pipe (if it does not already exist under the name ORA$RMAN_pipe_IN).

  2. Put the desired commands on the input pipe. In pipe mode, RMAN issues message RMAN-00572 when it is ready to accept input instead of displaying the standard RMAN prompt.

  3. Start RMAN with the PIPE option, and specify TIMEOUT 0. For example, enter:

    % rman PIPE abc TARGET / TIMEOUT 0
    
  4. RMAN reads the commands that were put on the pipe and executes them by using DBMS_PIPE.PACK_MESSAGE and DBMS_PIPE.SEND_MESSAGE. When it has exhausted the input pipe, RMAN exits immediately.

  5. Read RMAN output from the output pipe by using DBMS_PIPE.RECEIVE_MESSAGE and DBMS_PIPE.UNPACK_MESSAGE.

    See Also:

    Oracle Database PL/SQL Packages and Types Reference for documentation on the DBMS_PIPE package