1 Introduction to the Database Upgrade Process

Overview of the Database Upgrade Process

This section includes an overview of the major steps required to upgrade an existing Oracle database to the new Oracle Database 11g release. These procedures transform an existing Oracle Database system (including associated applications) into an Oracle Database 11g Release 2 (11.2) system. Oracle Database 11g Release 2 (11.2) is compatible with all earlier Oracle Database releases. Therefore, databases upgraded using the procedures described in this guide can work in the same manner as in earlier releases and, optionally, can leverage new Oracle Database 11g features and functions.

Oracle Database 11g Release 2 (11.2) supports the following tools and methods for upgrading a database to the new release:

• Database Upgrade Assistant (DBUA)

  Provides a graphical user interface (GUI) that guides you through the upgrade of a database. DBUA can be launched during installation with the Oracle Universal Installer, or you can launch DBUA as a standalone tool at any time in the future.

  Note:

  DBUA is the recommended method for performing a major release upgrade or patch release upgrade.

• Manual upgrade using SQL scripts and utilities

  Provides a command-line upgrade of a database, using SQL scripts and utilities.

• Export and Import utilities

  Uses the Oracle Data Pump Export and Import utilities, available as of Oracle Database 10g, or the original Export and Import utilities, to perform a full or partial export from your database, followed by a full or partial import into a new Oracle Database 11g database. Export/Import can copy a subset of the data, leaving the database unchanged.

• CREATE TABLE AS SQL statement

  Copies data from a database into a new Oracle Database 11g database. Data copying can copy a subset of the data, leaving the database unchanged.

These tools and methods are described in more detail in "Choose an Upgrade Method".

The major steps in the upgrade process are illustrated in Figure 1-1.

Figure 1-1 Upgrade Steps

Description of "Figure 1-1 Upgrade Steps"

The following list outlines the major steps performed during the upgrade process. Detailed instructions are provided in the appropriate chapters later in this guide.

Step 1: Prepare to Upgrade

• Become familiar with the features of the new Oracle Database 11g release.

• Determine the upgrade path to the new release.

• Choose an upgrade method.

• Choose an Oracle home directory for the new release.

• Develop a testing plan.

• Prepare a backup strategy.

Step 2: Test the Upgrade Process

• Perform a test upgrade using a test database. The test upgrade should be conducted in an environment created for testing and should not interfere with the actual production database.

Step 3: Test the Upgraded Test Database

• Perform the tests you planned in Step 1 on the test database and on the test database that was upgraded to the new Oracle Database 11g release.

• Compare results, noting anomalies between test results on the test database and on the upgraded database.

• Investigate ways to correct any anomalies you find and then implement the corrections.

• Repeat Step 1, Step 2, and the first parts of Step 3, as necessary, until the test upgrade is completely successful and works with any required applications.

Chapter 2, "Preparing to Upgrade" provides detailed information about Steps 1 through 3.

Step 4: Prepare and Preserve the Production Database

• Prepare the current production database as appropriate to ensure the upgrade to the new Oracle Database 11g release is successful.

• Schedule the downtime required for backing up and upgrading the production database.

• Back up the current production database. Perform a full or an incremental backup, as necessary, to ensure your database is protected against data loss.

Step 5: Upgrade the Production Database

• Upgrade the production database to the new Oracle Database 11g release.

• After the upgrade, perform a full backup of the production database and perform other post-upgrade tasks.

Chapter 3 describes Steps 4 and 5 when using DBUA or when performing a manual upgrade. Chapter 4 describes the backup procedure after the upgrade and other post-upgrade tasks.

Step 6: Tune and Adjust the New Production Database

• Tune the new Oracle Database 11g production database. The new production database should perform as well as, or better than, the database prior to the upgrade. Chapter 4, "After Upgrading to the New Release" describes these adjustments.

• Determine which features of the new Oracle Database 11g release you want to use and update your applications accordingly.

• Develop new database administration procedures, as needed.

• Do not upgrade production users to the new release until all applications have been tested and operate properly. Chapter 5, "Upgrading Your Applications" describes considerations for updating applications.

During the upgrade, consider running multiple releases of the database software so you can use the existing release as your production environment while you test the new release. See "Running Multiple Oracle Releases".

Oracle Release Numbers

This guide describes moving between different releases of the Oracle Database server. Figure 1-2 describes what each part of a release number represents.

Figure 1-2 Example of an Oracle Release Number

Description of "Figure 1-2 Example of an Oracle Release Number"

When a statement is made in this guide about a major database release number, the statement applies to all releases within that major database release. References to Oracle Database 11g include Oracle Database 11g Release 1 (11.1) and Oracle Database 11g Release 2 (11.2); references to Oracle Database 10g include Oracle Database 10g Release 1 (10.1) and Oracle Database 10g Release 2 (10.2); references to Oracle9i include Oracle9i Release 1 (9.0.1) and Oracle9i Release 2 (9.2).

Similarly, when a statement is made in this guide about a maintenance release, the statement applies to all component-specific (also referred to as patchset releases) and platform-specific releases within that maintenance release. So, a statement about Oracle9i Release 2 (9.2) applies to release 9.2.0.1, release 9.2.0.2, and all other platform-specific releases within Oracle9i Release 2 (9.2).

Compatibility and Interoperability

This section describes compatibility and interoperability issues that may arise because of differences between Oracle Database releases. These differences might affect general database administration and existing applications.

This section covers the following topics:

• What Is Compatibility?

• What Is Interoperability?

SQL> SELECT name, value FROM v$parameter
         WHERE name = 'compatible';

Using Optimal Flexible Architecture (OFA)

Oracle recommends the Optimal Flexible Architecture (OFA) standard for your Oracle Database installations. The OFA standard is a set of configuration guidelines for efficient and reliable Oracle databases that require little maintenance.

OFA provides the following benefits:

• Organizes large amounts of complicated software and data on disk to avoid device bottlenecks and poor performance

• Facilitates routine administrative tasks, such as software and data backup functions, which are often vulnerable to data corruption

• Alleviates switching among multiple Oracle databases

• Adequately manages and administers database growth

• Helps to eliminate fragmentation of free space in the data dictionary, isolates other fragmentation, and minimizes resource contention.

If you are not currently using the OFA standard, then switching to the OFA standard involves modifying your directory structure and relocating your database files.

Converting Databases to 64-bit Oracle Database Software

If you are installing 64-bit Oracle Database 11g software but were previously using a 32-bit Oracle Database installation, then the database is automatically converted to 64-bit during a patch release or major release upgrade to the new Oracle Database 11g release.

However, you must perform the following manual tasks:

• Increase initialization parameters affecting the system global area, such as SGA_TARGET and SHARED_POOL_SIZE, to support 64-bit operations.

• Reconnect after starting up the database so that a new session is created with the appropriate 64-bit initialization. For example:

  CONNECT  AS SYSDBA
  STARTUP UPGRADE
  CONNECT  AS SYSDBA
  SPOOL UPGRADE.LOG
  @catupgrd.sql
  

About Rolling Upgrades

A rolling upgrade upgrades different databases, database instances of the same database, or ASM instances in an Oracle Real Application Clusters (Oracle RAC) environment one at a time, without stopping the database. Depending on the method you choose to perform a rolling upgrade, you can upgrade the Oracle Database software or ASM instances, apply patchsets, or apply individual patches (sometimes referred to as one-off patches), incurring little or no database downtime.

Table 1-2 summarizes the various methods for performing rolling upgrades. Also, see Oracle Database High Availability Best Practices for help choosing a method to perform database upgrades.

Moving From the Standard Edition to the Enterprise Edition

If you have a Standard Edition database at a release prior to the new Oracle Database 11g release, then you can change it to an Enterprise Edition database by installing the Enterprise Edition and following the normal upgrade procedures, as described in this guide.

To change your existing Standard Edition database to an Enterprise Edition database, follow these steps:

1. Ensure that the release number of your Standard Edition server software is the same release as the Enterprise Edition server software.

   For example, if your Standard Edition server software is release 11.1.0.6, then you should upgrade to release 11.1.0.6 of the Enterprise Edition.

2. Shut down your database.

3. If your operating system is Windows, then stop all Oracle services, including the OracleServiceSID Oracle service, where SID is the instance name.

4. Deinstall the Standard Edition server software.

5. Install the Enterprise Edition server software using the Oracle Universal Installer.

   Select the same Oracle home that was used for the de-installed Standard Edition. During the installation, be sure to select the Enterprise Edition. When prompted, choose Software Only from the Database Configuration screen.

6. Start up your database.

Your database is now upgraded to the Enterprise Edition.

Moving From the Enterprise Edition to the Standard Edition

You cannot use the procedure described in "Moving From the Standard Edition to the Enterprise Edition" to convert an Enterprise Edition database to a Standard Edition database. The Enterprise Edition contains data dictionary objects which are not available in the Standard Edition. If you just install the Standard Edition software, then you will end up with data dictionary objects which are useless. Some of them might be invalid and possibly create problems when maintaining the database.

The only way to properly convert from an Enterprise Edition database to a Standard Edition database is through an Export/Import operation. The Export/Import operation does not introduce data dictionary objects specific to the Enterprise Edition, because the SYS schema objects are not exported. Oracle recommends using the Standard Edition Export utility to export the data.

After the Import in the Standard Edition database, you are only required to drop all user schemas related to Enterprise Edition features, such as the MDSYS account used with Oracle Spatial.

Upgrading from Oracle Database Express Edition to Oracle Database

To upgrade Oracle Database 10g Express Edition (Oracle Database XE) to Oracle Database 11g, you need to install Oracle Database 11g on the same system as Oracle Database XE and use the Database Upgrade Assistant to perform the upgrade.