Lesson 1

I am a DBA who needs to analyze installation and configuration. What does a DBA need to take into consideration when upgrading from Oracle 11g to Oracle 12c?
Upgrading an Oracle database from version 11g to 12c is a critical process that necessitates careful planning and execution. Database Administrators (DBAs) should consider several key factors throughout this process to ensure a smooth and successful upgrade.

1. Pre-Upgrade Considerations: A DBA should first analyze the current Oracle 11g environment, its setup, data volume, and usage patterns. Key factors to evaluate include: Compatibility: Ensure all applications, interfaces, and systems interacting with the Oracle 11g database are compatible with Oracle 12c. If not, these applications may need to be upgraded or adapted.Hardware Requirements: Oracle 12c may have different hardware requirements than Oracle 11g. Ensure your current hardware can handle the new version, and upgrade if necessary. Performance Benchmarks: Establish baseline performance metrics on the Oracle 11g system. These benchmarks can be used later to compare with Oracle 12c's performance.
2. Planning the Upgrade: Consider the upgrade method that best suits your environment. Oracle provides several options, including:
   1. Database Upgrade Assistant (DBUA)
   2. Manual Upgrade
   3. Export/Import (Data Pump)
   4. Remote cloning and plug-in
   5. Transportable Tablespaces
   6. Oracle GoldenGate
   Each of these methods has its own benefits, drawbacks, and prerequisites, so you must thoroughly understand your organization's needs and constraints to choose the most suitable one.
3. Backup Strategy: Before starting any upgrade process, ensure you have a comprehensive backup of your Oracle 11g database. The backup should include all data files, control files, redo logs, and configuration files. This backup will be critical for disaster recovery in case something goes wrong during the upgrade.
4. Upgrade Process: Regardless of the chosen upgrade method, the general process involves installing the Oracle 12c software, preparing the Oracle 11g database, upgrading the database, and then performing post-upgrade tasks. Installing Oracle 12c Software: Install the new Oracle Database 12c software in a new Oracle home. Make sure to choose the right options based on your specific use-case. Preparing the Oracle 11g Database: This includes tasks such as purging the recycle bin, updating or gathering statistics, validating the database, and backing up the database. Upgrading to Oracle 12c: Depending on your chosen upgrade method, perform the upgrade. Monitor the process for any errors or issues.
5. Post-Upgrade Considerations: After the upgrade, there are some additional tasks to ensure the health and stability of the new Oracle 12c environment:
   
   1. Database Health Check: Check the database's health by using tools like Oracle Enterprise Manager and Automatic Workload Repository (AWR). Also, check alert logs and trace files for any unusual entries.
   2. Performance Tuning: Compare the performance of Oracle 12c with the previously recorded Oracle 11g benchmarks. Tune any SQL queries or processes that do not perform as well in the new version.
   3. Retesting Applications: Thoroughly test all applications that interact with the Oracle database. This includes testing all SQL queries and stored procedures to ensure they function as expected in the new version.
   4. Update Documentation: Update all relevant system and operational documentation to reflect the new Oracle 12c environment.

By adhering to these principles, a DBA can execute a systematic and effective upgrade from Oracle 11g to Oracle 12c, mitigating risks and ensuring operational continuity throughout the process.

The first issue you will face when installing or upgrading to Oracle is how to approach configuration and installation.
Oracle has provided some improvements in its design of these processes, so your job will be a little easier than it was before. For example, prior to oracle, the Universal Installer was used to install most, but not all of Oracle's software, and its screens looked different on different operating systems. Now the Universal Installer looks the same on all platforms and is used to install any of Oracle's software, from the database to the network software. This is just one example of many changes that have been made in oracle to make installation and configuration a little easier. The point of this module is to familiarize you with these numerous changes.

Is the Universal Installer still used to view installed software in Oracle 13c?
Yes, the Oracle Universal Installer (OUI) can still be used to view installed software in Oracle 13c. To do this, open the OUI and click on the "Installation Location" screen. In the "Features Sets Installed at Selected Oracle Home" section, you will see a list of all the products that are installed in the selected Oracle home directory. You can also click on the "View" button to see more detailed information about each product. In addition to the OUI, you can also use the oinstall command to view installed software in Oracle 13c. To do this, open a command prompt and type the following command:

oinstall lsinventory

This will list all of the products that are installed on your system, along with their version numbers and installation directories. The OUI and oinstall commands are both useful tools for viewing installed software in Oracle 13c. The OUI provides a more graphical interface, while oinstall is a text-based command. The best tool to use will depend on your personal preferences and needs.

By the end of the module you will be able to:

1. Use the Universal Installer to view currently installed software
2. Identify improvements to configuration
3. Describe the functions of the Database Configuration Assistant
4. Upgrade a database from Oracle8 to oracle using Universal Installer and the Database Migration Assistant
5. Describe how to use the Software Packager to handle distributed software installation

The next lesson looks at the Universal Installer which is Oracle's installation tool.