HOW TO

1. What is a rolling upgrade?

* It is a new ASM feature from Database 11g. ASM instances can be upgraded or patched using rolling upgrade features.

* This enables us to patch or upgrade ASM nodes in a clustered environment without affecting database availability.

* During a rolling upgrade we can maintain a functional cluster while one or more of the nodes in the cluster are running in different software versions.

2. What happens when you use startup UPGRADE ?

* The UPGRADE keyword enables you to open a database based on an earlier Oracle Database release.

* It also restricts logons to AS SYSDBA sessions, disables system triggers, and performs additional operations that prepare the environment for the upgrade.

* Once the database is started in upgrade mode, only queries on fixed views execute without errors until after the catupgrd.sql script is run.

3. What is the difference between startup Upgrade and Migrate ?

STARTUP MIGRATE: Used to upgrade a database till 9i.

STARTUP UPGRADE: From 10G we are using startup upgrade to upgrade the database.

4. What happens internally when you use startup upgrade/migrate? It will adjust a few database (init) parameters (irrespective of what you have defined) automatically to certain values in order to run upgrade scripts smoothly. In other words,it will issue a few alter statements to set certain parameters which are required to complete the upgrade scripts without any issues.

Upgrade Steps

Pre-Upgrade Steps:

* Review the Oracle Database Upgrade Guide for the target version.

* Check the certification matrix for compatibility with your operating system and other components.

* Backup the database using appropriate methods (physical or logical backups).

* Analyze the database for potential upgrade issues using the Pre-Upgrade Information Tool (preupgrade.jar).

Upgrade Planning:

* Determine the upgrade method (in-place upgrade or migration) based on your current setup and target version.

* Plan for downtime or minimal downtime based on the chosen upgrade method.

* Prepare rollback procedures in case the upgrade fails or encounters issues.

Upgrade Process:

* Install the Oracle Database software for the target version on the server.

* Stop all database-related services and applications accessing the database.

* Execute the Database Upgrade Assistant (DBUA) or perform a manual upgrade using SQL scripts. $ORACLE_HOME/perl/bin/perl $ORACLE_HOME/rdbms/admin/catctl.pl -d $ORACLE_HOME/rdbms/admin -l /home/oracle/ -n 4 catupgrd.sql

* Follow the prompts or scripts to upgrade the database software and data dictionary to the target version.

* Monitor the upgrade progress for any errors or warnings.

Post-Upgrade Steps:

* Run post-upgrade scripts as recommended by Oracle for the target version.

Run “postupgrade_fixups.sql” .

To fix the manual error related to timezone

* Perform functional and performance testing to ensure the upgraded database operates as expected.

* Update client connections, configuration files, and application settings to point to the upgraded database.

* Verify data integrity and consistency after the upgrade.

* Document the upgrade process, including any issues encountered and resolutions applied.

For 12cR2, the new timezone is 26. So once the db upgrade is completed, we have to upgrade the dst timezone from 14 to 26 DownloadDBMS_DST_scriptsV1.zip file from metalink.

If an Oracle bundle patch or patch set update (PSU or BP) is installed in the Oracle home, this script will automatically applies those patch set update to the database. Execute utlrp.sql script to compile invalid objects. Set COMPATIBLE parameter value for 12.2.0 as well as start the listener with 12.2 home. Finally to check the component and version using dba_registry view.

Finalize and Cleanup:

* Remove any temporary files or backup copies created during the upgrade process.

* Update documentation, including version numbers and upgrade dates.

* Communicate the successful upgrade to relevant stakeholders and users.

* Monitor the upgraded database for any post-upgrade issues and address them promptly.