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Oracle® Database 2 Day DBA
11g Release 1 (11.1)

Part Number B28301-01
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Upgrading a Database

Use Database Upgrade Assistant (DBUA) to upgrade an existing database to the current release of Oracle Database.

This section contains these topics:

Overview of Database Upgrade Assistant

Database Upgrade Assistant (DBUA) guides you through the upgrade process and configures your database for the new release. DBUA automates the upgrade process and makes appropriate recommendations for configuration options such as tablespaces and redo logs.

DBUA can be used to upgrade databases created using any edition of the Oracle Database software, including Express Edition (XE) databases.

Pre-Upgrade Checks

DBUA does not begin the upgrade until it completes all of the following pre-upgrade steps:

  • Checks for any invalid user accounts or roles

  • Checks for any invalid data types or invalid objects

  • Checks for any desupported character sets

  • Checks for adequate resources, including rollback segments, tablespaces, and free disk space

  • Checks for any missing SQL scripts needed for the upgrade

  • Backs up all necessary files (optional)

Automated Upgrade Tasks

After completing the pre-upgrade steps, DBUA automatically performs the following tasks:

  • Modifies or creates new required tablespaces

  • Invokes the appropriate upgrade scripts

  • Archives redo logs

  • Disables archiving during the upgrade phase (to improve performance)

While the upgrade is running, DBUA shows the upgrade progress for each component. DBUA writes detailed trace and log files and produces a complete HTML report for later reference. To enhance security, DBUA automatically locks new user accounts in the upgraded database. DBUA then proceeds to create new configuration files (initialization parameter and listener files) in the new Oracle home.

Support for Oracle Real Application Clusters

DBUA is fully compliant with Oracle Real Application Clusters (Oracle RAC) environments. In Oracle RAC environments, DBUA upgrades all database and configuration files on all nodes in the cluster.

Support for Automatic Storage Management

DBUA supports upgrades of databases that use Automatic Storage Management (ASM). If an ASM instance is detected, then you have the choice of updating both the database and ASM or only the ASM instance.

Support for Silent Mode

DBUA supports a silent mode of operation in which no user interface is presented to the user. Silent mode enables you to use a single statement for the upgrade.

Database Versions Supported by DBUA

DBUA supports the following versions of Oracle Database for upgrading to Oracle Database 11g Release 1 (11.1):

  • Oracle9i Release 2 ( and beyond

  • Oracle Database 10g Release 1 (10.1)

  • Oracle Database 10g Release 2 (10.2)

If your database version is not in this list, then you need to upgrade first to the closest release listed. You can then upgrade the database to Oracle Database 11g Release 1 (11.1).

Starting DBUA

If you install the Oracle Database software only and specify that you are upgrading an existing database to the new Oracle Database release, then DBUA is launched automatically at the end of the software installation. You can then continue as described in "Upgrading a Database Using DBUA".

If you perform a software-only installation and do not upgrade your database at that time, then you can do so later by launching DBUA.

Be aware of the following before you begin using DBUA:

  • You must run Net Configuration Assistant (NETCA) before running DBUA.

  • If the database instance is not running, then DBUA will try to start the instance with the default initialization parameter file. If that fails, then you will be prompted to provide the name of the correct initialization parameter file or to start the instance. If the instance is already up and running, then DBUA connects to it.

  • If you stop the upgrade, but do not restore the database, then you should not restart DBUA until you start up the existing database in UPGRADE mode using the Oracle Database 11g software. You cannot go back to the original server unless you restore your database.

    If you restore your database manually (not using DBUA), then remove the following file before starting DBUA:


    The presence of this file indicates to DBUA that this is a rerun operation.

To start DBUA on Microsoft Windows:

  • Click Start, then select Programs, then Oracle - HOME_NAME, then Configuration and Migration Tools, and then select Database Upgrade Assistant.

    The Database Upgrade Assistant: Welcome window appears.

To start DBUA on any supported platform:

  1. Open a command window.

  2. (Linux and UNIX systems only) Set the required environment variables by running the script oraenv (for the Bourne, Korn, or Bash shells) or coraenv (for the C shell).

    These scripts are typically located in the /usr/local/bin directory. They may prompt you for the desired value of the ORACLE_SID environment variable. If so, supply the system ID (SID) that you chose when you installed Oracle Database. The default SID that the installer typically suggests is orcl.

  3. (Linux and UNIX systems only) Either ensure that the Oracle_home/bin directory is in your PATH environment variable, or change directory to Oracle_home/bin.

  4. Enter the following command:


    The Database Upgrade Assistant: Welcome window appears.


    The dbua executable is typically found in your Oracle_home/bin directory.

See Also:

Oracle Database Upgrade Guide for more information about Database Upgrade Assistant

Upgrading a Database Using DBUA

Complete the following steps to upgrade a database using DBUA. If you need help at any window or want to consult more documentation about DBUA, then click the Help button to access the online Help.

To upgrade a database using DBUA:

  1. Start DBUA. See "Starting DBUA".

  2. At the Welcome window of DBUA, make sure the database being upgraded meets the specified conditions. Then, click Next.

    If an ASM instance is detected on the system, then the Upgrade Operations window appears. If no ASM instance is detected, then the Databases window appears.

  3. (ASM detected only) From the Upgrade Operations window you can choose to upgrade only the ASM instance or the database. If you choose to upgrade the database and if the database is using ASM, then DBUA will ask you whether or not to upgrade the ASM instance along with the database. Oracle recommends that you upgrade the database and ASM in separate DBUA sessions, in separate Oracle homes.

  4. At the Databases window, select the database you want to upgrade from the Available Databases table. Then, click Next.

    You can select only one database at a time. If you are running DBUA from a user account that does not have SYSDBA privileges, then enter the user name and password credentials to enable SYSDBA privileges for the selected database.

  5. DBUA displays a message saying it is getting database information. DBUA analyzes the selected database, performing pre-upgrade checks and displaying warnings as necessary:

    • It checks for any online redo log files of a size less than 4 megabytes (MB). If such files are found, then DBUA gives the option to drop or create new online redo log files.

    • It checks the initialization parameter file for any obsolete or deprecated initialization parameters.

    If no problems are found, then the Diagnostic Destination window appears.

  6. In the Diagnostic Destination field, do one of the following:

    • Leave the setting at its default value, which is the Oracle base directory.

    • Enter a new destination.

    • Click Browse and select a new destination.

    Diagnostic Destination is the default location to store Oracle trace and diagnostic files. It replaces the initialization parameter settings for background dump destination, user dump destination and core dump destination from earlier Oracle Database releases.

    Click Next.

    The Move Database Files window appears.

  7. Do one of the following:

    • Select Do Not Move Database Files as Part of Upgrade.

    • Select Move Database Files During Upgrade.

      If you choose to move database files, then you must also select either File System or Automatic Storage Management (ASM).

    Click Next.

    The Recompile Invalid Objects window appears.

  8. (Optional) Select Recompile invalid objects at the end of upgrade and modify the value of degree of parallelism.

    When you upgrade your database to the new Oracle Database release, many of the PL/SQL modules in the database become invalid. By default, Oracle Database will recompile invalid PL/SQL modules as they are used, but this takes time and can result in poor performance. To eliminate these performance issues, select Recompile invalid objects at the end of upgrade. All the invalid PL/SQL modules will be recompiled immediately after the upgrade is performed. The task of recompiling all the invalid PL/SQL modules in your database can take a significant amount of time and increase the time it takes to complete your database upgrade.

    If you have multiple CPUs, then DBUA automatically adds a Degree of Parallelism menu to the Recompile Invalid Objects window. Parallel processing reduces the time it takes to recompile all the invalid PL/SQL modules in your database. DBUA automatically sets the degree of parallelism to one less than the number of available CPUs. You can select a different value from the menu.


    Selecting Recompile invalid objects at the end of upgrade is equivalent to running the Oracle_home/rdbms/admin/utlrp.sql script, which is used to recompile stored PL/SQL and Java code.

    Click Next.

    The Backup window appears.

  9. Select one of the following options:

    • I have already backed up my database.

    • I would like this tool to back up the database.

      If you use DBUA to back up your database, then DBUA makes a copy of all database files in the directory that you specify in the Backup Directory field. DBUA performs this consistent backup automatically after it shuts down the database and before it begins the upgrade process. The backup does not compress the database files.

      In the Backup Directory field, do one of the following:

      • Leave the setting at its default value

      • Enter a different valid file system path. You cannot specify a raw device for the backup files.

      • Click Browse and select a new backup destination.

    Oracle strongly recommends that you back up your database before starting the upgrade. If errors occur during the upgrade, then you may need to restore the database from the backup.

    In addition to creating a backup of your database, DBUA creates an executable script in the directory specified in the Backup Directory field. If needed, you can use the executable script appropriate to your system to restore the database files:

    • Microsoft Windows: db_name_restore.bat

    • Linux or UNIX systems:

    Click Next.

    The Recovery Configuration window appears.

  10. In the Flash Recovery Area field, do one of the following:

    • Leave the setting at its default value

    • Enter a different Flash Recovery Area

    • Click Browse and select a different Flash Recovery Area.

    The Flash Recovery Area can be used to recover data that would otherwise be lost during a failure. This location is also used by Enterprise Manager if you have enabled local management and daily backups on the Database Control Management Options page.

    In the Flash Recovery Area Size field, select the units you want from the list and do one of the following:

    • Leave the setting at its default value.

    • Enter a different value for Flash Recovery Area Size.

    • Use the up and down arrows to set a different Flash Recovery Area Size.

    In the Recovery Configuration window, you specify a Flash Recovery Area and enable archiving. It is important to configure these features for your database so you can recover your data in the event of a failure.

    Click Next.

    The Summary window appears.

  11. Review the list the initialization parameters that will be set for the database during the upgrade. Click Back to correct any errors, or click Finish.


    The database will not be available for general use during the upgrade process that begins when you click Finish.

    A Progress window appears and DBUA begins to perform the upgrade.

  12. You might encounter error messages with Ignore and Abort choices:

    • Ignore - Ignores the error, skips the current step, and proceeds with the upgrade. The ignored errors are logged and shown later in the summary. After the upgrade is complete, you can fix the problem, restart DBUA, and complete the skipped steps.

    • Abort - Stops the upgrade process. DBUA prompts you to restore the database if the database backup was performed by DBUA. After the database has been restored, correct the error and restart DBUA to perform the upgrade again. If you do not restore the database, then DBUA leaves the database in its current state so that you can proceed with a manual upgrade.

    After the upgrade has completed, the following message is displayed:

    Upgrade is complete. Click "OK" to see the results of the upgrade.

    Click OK.

    The Upgrade Results window appears.

  13. Examine the results of the upgrade. The upgrade results summary describes the original and upgraded databases and changes made to the initialization parameters.

    The upgrade results also include an Upgrade Details section that describes the steps performed during the database upgrade. This section provides each step name, the log file for the step, and the status. In some cases, you can click the status to display details about the execution step. The Upgrade Details section also includes the directory where the various log files are stored after the upgrade. You can examine any of these log files to obtain more details about the upgrade process.


    An HTML version of the Upgrade Results is also saved in the log files directory.
  14. Click Configure Database Passwords.

    The Password Management dialog box appears.

  15. The Password Management dialog box enables you to change the default password for a user after you upgrade the database.


    To prevent unauthorized use of the database, change all user passwords immediately after you upgrade your database.

    Click the Lock Account? column for a user to lock or unlock an account. A check mark indicates that the account is locked.

    Enter a new password for a user in its New Password column.

    Confirm the new password by entering it in the Confirm Password column.

    Click OK to return to the Upgrade Results window.

  16. Click Restore if you are not satisfied with the upgrade results.

    Depending on the method you used to back up your database, the restore operation performs one of the following tasks:

    • If you used DBUA to back up your database, then clicking Restore copies the original database files and the original database settings from the backup.

    • If you used your own backup procedure to back up the database, then clicking Restore copies only the original database settings. To restore the database itself, copy the datafiles from the backup you created using your own backup utilities.

    Click Close to quit DBUA if you are satisfied with the upgrade results.

    DBUA removes the entry of the upgraded database from the old listener.ora file and restarts the listener.


If you retain the old Oracle Database software, then never start the upgraded database with it. Only start the database with the executable files in the new Oracle Database installation. Also, before you remove the old Oracle Database environment, make sure you relocate any datafiles in that environment to the new Oracle Database environment. See Oracle Database Administrator's Guide for information about relocating datafiles.

See Also:

Oracle Database Upgrade Guide for information about additional tasks that should be completed after upgrading a database